FIM NEWS -- history of main user-visible changes in FIM.

                Version 0.7.1

A release with small fixes at build, test, and runtime:

 * Documentation and self-documentation improved and updated
 * Command  "help '/str'"  will also search on occurrences of 'str' among set variable identifiers and their help
 * Default binding of 'N' and 'P' changed to be more flexible: either page goto or category or directory goto
 * Fix: GTK (-o gtk) mode had mouse coordinates slightly wrong (were including the menu bar)
 * Fix: SDL mode (-o sdl) now allows fim (emergency) exit per windows quit button also in case no key is bound to 'quit'
 * Fix: now in 'goto "+1p" "+1f"' the page jump takes precedence over the file jump
 * Fix: had potential memory error after --sort and with absent files
 * Fix: Before testing PS pr PDF functionality, Makefile will check if respective sample files are there
 * Fix: --load-image-descriptions-file (-D)  was opening files in append mode for no reason
 * Fix: --mark-from-descriptions-file  was opening files in append mode for no reason
 * Fix: don't omit last Tab multiple autocompletion entry
 * Fix: alias command to complain if being provided with one argument which is no alias
 * Fix: more resilience on missing groff
 * More and better tests
 * Fix: SDL-1.2 compilation fix
 * Fix: 32-bit build fix for GTK3
 * Fix: pass CFLAGS, CPPFLAGS and LDFLAGS to helper programs
 * Fix: configure was disabling crop tests by mistake
 * Fix: configure now uses PKG_CONFIG to determine pkg-config
 * Fix: configure had mistake leading to a few wrong src/Makefile rules
 * Fix: configure poppler check: improved diagnostics, reflecting closer required headers, extend check to poppler-cpp
 * Fix: in configure and Makefile when building with emscripten (WebAssembly)
 * Fix: input of non-ASCII values to -k and -K was not being carried out correctly on systems with char being unsigned (e.g. aarch64)
 * Misc minor fixes (e.g.: in tests, djvu error verbosity, readline, configure, configuration ...)

                Version 0.7.0

A major release:

 * New graphical windowed output mode via GTK3 (similar to SDL, but with menus), selected with -o gtk
 * -o =OPTS / --output-device==OPTS / --output-device =OPTS will pass OPTS to the auto-selected output device
 * Key presses passed at startup via the -k and -K options are executed in the order the options appear
 * When auto-selecting the output device, also take in consideration environment variable  WAYLAND_DISPLAY
 * Closer behaviour of readline and history keys across the graphical modes
 * --slideshow option now accepts decimal values
 * Given string variables a and b, a-b is the value with all occurrences of regexp b removed from a (experimental)
 * Introduce expansion-only variable description syntax "#!fim:@var=VAL"
 * Support @-expansion of "@id" within "VAL" of "#!fim:var@=VAL" or "#!fim:@var@=VAL"
 * When loading via an external converter, keep track of it in i:_external_decoder_program
 * Load XCF (Gimp) files via the xcf2pnm utility
 * Files with name ending in .NEF are now viewable via wrapper call to dcraw (if present)
 * Support for reading QOI files via libqoi (experimental)
 * Support for reading AVIF images via libavif (experimental)
 * Support for reading WebP images via libwebp (experimental)
 * Searches via '/' or '?' are now replayable via "recording 'repeat_last'"
 * Simultaneous specification of file and page to 'goto' now possible
 * Enable descriptions to be searched in "goto /PATTERN/" by keeping the newly introduced 'D' in _re_search_opts
 * If there's only one file, passing a numeric argument to 'goto' will do a page jump
 * Fix with SDL2 (-o sdl): reduce chance of intercepting Tab key during window switch
 * Mouse scroll in SDL (-o sdl) and GTK (-o gtk) modes
 * Mouse click and help grid map support for -o ca
 * Move-trigged pan support for -o ca=w
 * Specify a dithering algorithm  DA  as string or numeric index in  -o ca=d:DA  (e.g. -o ca=d:0)
 * Scaling fix when starting with -o ca
 * Introduce variable _lastpageindex to allow jump to last page
 * Variable "_device_string" now contains the entire output device (graphical mode) specification
 * The expandos of the form %:VAR: will first check for i:VAR, and then for VAR (experimental)
 * Add configure option  --disable-mouse
 * Bugfix: in some cases the "#!fim:VAR=..." description syntax would not propagate VAR properly
 * Fixes in the configure script (remove bashisms by SDL version recognition)
 * Bugfix: configure --disable-system  was bogus
 * Bugfix: avoid terminal clutter after interruption of "endless_slideshow"
 * Bugfix: avoid memory leak while decoding PDF
 * Improve error handling when encountering corrupt or unsupported TIFF files
 * More tests
 * FIM requires a compiler supporting at least C++11
 * Documentation and self-documentation improved and updated

                Version 0.6-rc2

 * File dropping support in SDL2 mode and more responsive readline mode

                Version 0.6-rc1

 * Experimental support for SDL2.

                Version 0.6-rc0

A summary of major improvements:

 * Colour ASCII-Art output via libcaca, selected with -o ca
 * better mechanism to determine best output device
 * font magnification by integer factors, good for higher resolutions
 * runtime font selection
 * new options to commands "scale", "goto", "limit", "list", ...
 * 'limit' view to relevant image files based on properties (like in 'mutt')
 * pass key presses to be automated at startup with -k and -K options
 * pretty free from memory leaks
 * -X switch inhibits custom external converters
 * new powerful subcommand "list 'mark'"
 * new command-line switches (--sort..) to sort the initial files list
 * use mipmaps for faster scaling
 * open files from a files list with -L
 * load image description files with -D 
 * background recursive scan and load of files with -B
 * search files at startup based on description with -/ and --//
 * new verbosity and debug options
 * better error handling when encountering corrupt files
 * fast in-place switch to high-res file via --load-shadow-directory 
 * improvements in -o aa (ASCII-art output device with aalib)
 * more options for window size selection in -o sdl
 * Keys F1,F2,F3,F4,F5,F6,F7,F8,F9,F10,F11,F12 now usable with 'bind'

In detail, in no particular order:

 * Experimental support for SDL2.
 * More responsive readline mode.
 * Switch --resolution 'fullscreen' appends 'W' if in SDL mode.
 * If a "matrix market" file is loaded, its rows, columns and nnz are image variables, too.
 * Introduce special 'early' form  -C =var=val  where variable var is assigned to unquoted and non-interpreted value val immediately.
 * Variable i:__exif_orientation renamed into i:_exif_orientation
 * Fix: --cd-and-readdir was not jumping back to first file.
 * Fix: --device option not ignored anymore.
 * Rename --no-etc-rc-file switch to --no-etc-fimrc-file .
 * fimgs: bunzip2, wget, and xz are now optional.
 * Bugfix: fimgs to properly remove temporary directory after loading downloaded files.
 * Misc small improvements in documentation text output and reporting (no cursor in post-search output line; misc messages).
 * Key 'Z' now assigned to 'sleep 1'.
 * Key 'Del' now assigned to 'list "remove"'.
 * Add -= as short form of the --no-auto-scale option.
 * Experimental: add command "crop", also activated after selecting the area by holding Shift and clicking with left mouse button (if running with -o sdl).
 * Add command "pan 'vsteps%' 'hsteps%'" and "'pan 'vsteps' 'hsteps'".
 * Keys F1,F2,F3,F4,F5,F6,F7,F8,F9,F10,F11,F12 are now usable with 'bind' with modes -o aa, -o ca, -o dumb.
 * Fix for -o sdl: when flipped or mirrored, it used to draw a smaller box by mistake.
 * Only filenames matching "^[/A-Za-z0-9_.][/A-Za-z0-9_.-]*$" can occur in a conversion command involving an external program.
 * --pread-cmd=command  substitutes any occurrence of '{}' in command with the actual filename, executes the result and reads an image from its stdout.
 * -o fb=S will not tolerate running under screen.
 * Bugfix in --script-from-stdin now prevents possible crashes.
 * Removed configure options --enable-c++11 -- use CXXFLAGS instead.
 * Bugfix: 'autocmd_del' with no arguments would crash.
 * Bugfix: autocommand "PostHardcodedConfigLoading" now triggers even if --disable-fimrc .
 * Internals: considerably expanded 'make tests'.
 * Add command 'stderr', similar to 'stdout'.
 * This is the last FIM version supporting the C++03 standard.
 * Refresh configure and Makefile templates.
 * Build fixes for the MinGW environment.
 * man fim: improve manual contents (on ~/.fim_history, individual options, wording, etc.).
 * man fimrc: added a section with default aliases,
 * Where appropriate, 'make tests' uses 'timeout' to prevent possible hangs.
 * Switch  -K <chars>  aka  --chars-press <chars> simulates input of characters at startup.
 * Fix: slideshow function (e.g. `fim --slideshow=5 media/`) will now cycle forever, unless --once/-1 option specified (as in fbi).
 * Fix: after 'quit' no command shall execute anymore (unless in -F).
 * With SDL one can specify window size as percentage of allowed size (-o sdl=w55%), or draw a help grid map (-o sdl=h).
 * With SDL (-o sdl), center window by default.
 * Fix: now pressing keys "1n1n" will not execute 'n' 11 times, but twice.
 * configure --enable-debug is a developer option now.
 * libcaca (-o ca) mode is now complete and is the default ASCII Art mode.
 * Slideshow function (e.g `fim --slideshow=5 *.jpg`) now more responsive.
 * Arrow keys are now working in aalib (-o aa).
 * Bugfix with aalib (-o aa): don't truncate long lines.
 * Avoid memory leak in language parser.
 * Avoid console buffer memory corruption.
 * Eliminate a memory leak from file loading code. 
 * Eliminate memory leaks in PNG, JPG, TIFF, EXIF, and font decoding code.
 * Fix possibly broken `make -j` in rebuilding fimgs.man and fimrc.man.
 * Correct configure script check for regcomp() -- could lead to false negatives.
 * Don't break build on missing 'gs'.
 * Experimental: use --load-shadow-directory <dir> to add a "shadow directory".
   Then 'scale "shadow"' (bound to key '"') will substitute the current displayed image
   with that of the first same-named file located under a shadow directory.
 * When loading a directory, regular expression from default "_pushdir_re" variable now matches filenames with .webp extension.
 * Fix: `fim -c '/<pattern>'` was broken.
 * Add " INTEGER , INTEGER IDENTIFIER arguments" syntax to repeat a command 
   on each file in the interval and substitute its name to '{}' in the arguments
   to an iterated command IDENTIFIER.
 * If a key is bound to e.g. 'goto "+1F"', keep pressing it to accelerate (not if e.g. "+1f").
 * Internal fix: piping from external commands was using 0 instead of 'WNOHANG', leading to hanging.
 * Internal fix: error handling was missing.
 * fimgs now to handle tar.xz archives.
 * Reload automatically image on file change.
 * Command 'list' 'sort_var' 'var' to sort file list according to values of 'i:var'.
 * Command 'list' 'sort_comment' to sort file list according to 'i:_comment' value.
 * Add a --verbose-font-load switch to set '_fbfont_verbosity=1'.
 * Variable '_fbfont_verbosity' sets verbose font loading.
 * Fix: short options -b, -h, -R were not getting optional argument (e.g. -b1).
 * Key combination C-r now assigned to "reload ''".
 * Fix: symbol from fbi sources clashed with gcc-6 onwards, breaking compilation.
 * Key combination C-w assigned to setting auto-scaling to width.
 * Smoother scroll of large images.
 * If SSH_TTY set and no output device specified, give precedence to aalib, then libcaca.
 * Bugfix: in --as-text will avoid repeated reload of file.
 * Hardcoded font (if configured in) will serve as fallback font.
 * Add a --no-pipe-load / -X switch to _no_external_loader_programs=1;
 * Description variables beginning with '_' will not go into i: .
 * List variables in all i:* read from description file with "list 'vars|variables'".
 * Expansion of @variables and @# comments from description files.
 * The menu key in SDL mode shows a temporary mouse click actions menu.
 * Bugfix: description file reading was crashing due to wrong check.
 * Caption text of "_caption_over_image" takes at most half of the screen.
 * If _caption_over_image=3, image is possibly drawn below the caption.
 * The 'v' and 'S' keys now cause a redraw.
 * The description line can be of any length.
 * New configure option, defaulting to: --enable-paths-in-man; it generates man pages with configure specified paths (e.g. sysconfdir, docdir).
 * Fix: -s switch was broken.
 * Add a semicolon (;) to -C arguments if not present already.
 * Framebuffer console switch off while loading: configure with the 
   --enable-framebuffer-switch-while-loading switch to have it back.
 * Fix: configure would fail on --disable-aa and absent aalib.
 * Now configure has --enable-seek-magic by default. And is more verbose.
 * Command 'help' also shows key bindings, and give multiple answers if matching.
 * For each word following switch --help, an individual help message is shown.
 * Command 'goto' accepts multiple arguments; evaluating them until the first one triggering a jump.
 * Command goto {'-/'|'+/'}[C] jumps to a file based on character C (default 'S').
   If C is 's', to prev/next file with same directory name.
   If C is 'd', to prev/next file with directory name down the same hierarchy.
   If C is 'u', to prev/next file with directory name up the same hierarchy.
   If C is 'b', to prev/next file with same basename.
   If C is as above but uppercase, to the prev/next file not matching the criteria.
 * Accordingly, aliases 'next_file_dir_same', 'next_file_dir_other', 'next_file_dir_up',
   'next_file_dir_down', 'next_file_same_basename', 'prev_file_dir_same',
   'prev_file_dir_other', 'prev_file_dir_up' 'prev_file_dir_down' 'prev_file_same_basename'.
 * Fix: 'recording' command was not functioning properly.
 * Fix: don't pop back last command if "recording 'stop'" executed outside of recording mode.
 * Fix: won't clear recorded list if calling recording 'start' multiple times.
 * Specifying more than once any of -p -i - causes a warning.
 * New switch --verbose-interpreter to execute interpreter verbosely by setting adequately _debug_commands='ackC'.
 * Strings specified within single quotes have single quotes escaped, just as double quotes.
   So that e.g.: '\'hello\'' equals "'hello'" and "\"hello\"" equals '"hello"'.
 * Variable '_debug_commands' is now a string with several verbosity options.
 * Fix: misc fixes for --offset, e.g. avoiding probing for external loader programs.
 * Add --verbose-load option for verbose file loading.
 * -C '_seek_magic=..' probes whole range of specified signature when loading a file.
 * Fix in _seek_magic documentation.
 * Option --offset accepts numbers suffixed by one of K, M, and G for respectively kibi-, mebi-, and gibi- (2^10, 2^20 and 2^30) units.
 * Bugfix: --offset option was ignoring lower bytes-offset.
 * Fix: a check was missing in the PS decoder when reading from stdin.
 * Command 'pan' accepts '-' and '+' to jump to prev/next file if border is reached.
 * Command 'font' controls displayed font and scans font directories.
 * Keys '{' and '}' cycle through available consolefonts.
 * Variable _fbfont_magnify_factor scales text font at runtime.
 * Variable _fbfont_as_screen_fraction; if >0, font is scaled to exceed 1/_fbfont_as_screen_fraction of both width and height.  If _fbfont_as_screen_fraction<0, font scaling is fixed.
 * Keys '[' and ']' bound to new aliases "font_reduce" and "font_magnify".
 * Key '|' bound to new alias "toggle_font_auto_scale".
 * Switch -r {width:height} / --resolution {width:height} behaves as expected in SDL mode.
 * Variable _downscale_huge_at_load, if 1 (default), downscale automatically huge images at load time. To avoid loading images exceeding too much screen size.
 * Variable i:_buffered_in_tmpfile stores temporary decoding image filename, if any.
 * Internally load SVG files by invoking inkscape <file.svg> --without-gui --export-png <temp.png>. A file beginning with "<svg" is be considered an SVG (Scalable Vector Graphics).
 * Command 'scrollforward' skips a border if this is less than a fraction of the screen; this smoothes up documents reading. The fraction is one over '_scroll_skip_page_fraction', if >1; 1/16 if 1, no tolerance if <1.
 * Variable "_want_wm_mouse_ctrl" controls mouse click/movement behaviour in SDL mode.
 * Variable "_min_cached_images" is the minimum number of images to keep from eviction.
 * Commands  scale '<'  /  scale '>' shrinks/magnifies the image using cached mipmaps.
 * By default, show mouse cursor in full screen SDL mode.
 * Autocommand "PostInteractiveCommand" does not trigger anymore after 'quit' command.
 * In case of a CBZ,CBR,PDF,PS,DVI file, the fimgs script now uses '--autotop --autowidth'.
 * The fimgs script now probes for unrar-nonfree/rar/unrar-free (in this order).
 * Customize overlay text via variable '_caption_over_image_fmt'.
 * Command syntax 'goto {+|-}identifier[+]' (new) jumps to next file having a different value of i:identifier, also empty if without trailing `+'.
 * Command "limit '-set_union'" merges current limited list with the new one.
 * Command "limit '-merge'" merges current limited list with the new one.
 * Command "desc 'reload'" loads once again description files specified at the command line with --load-image-descriptions-file.
 * FIM only checks for filename duplicates if a sorting option is specified.
 * Switch -P/--text-reading fixed. Seems to be broken in version 0.5.
 * Command "color": "color 'negate'" and "color 'desaturate'" introduced.
 * Commands 'negate' and 'desaturate' deleted.
 * Command "color CVS" (CVS among 'protanopia', 'deuteranopia', 'tritanopia', 'p', 'd', 't') simulates a color vision deficiency; adding 'daltonize' applies a tentative color correction;  "color 'colorblind'" is short for "color 'deuteranopia'".
 * Command "color 'identity'": populate the image with 'RGB identity' pixels.
 * Introduce a "#!fim:/=dir" special description line to specify directory prepended to basename.
 * Introduce a "#!fim:\=dir" special description line to specify directory prepended to filepath.
 * Command limit '-list'      lists existing variables identifiers as set via 'desc'
 * Command limit '-list' 'id' lists existing values for instances of variable 'id' as set via 'desc'
 * Command "limit '~i' MINIDX[-MAXIDX]", with MINIDX and MAXIDX numbers (possibly with K as x 1000 multiplier) restricts filenames list to the specified interval.
 * Command "limit '~d'", limits to files having exact current file's modify date +- one day.
 * Command "limit '~z'" limits to files having same file size as the current.
 * Command "limit '~z' MINSIZE[-MAXSIZE]", with MINSIZE and MAXSIZE numbers with possibly K (x 1024) or M (x 1024 1024) multipliers, limits according to file size.
 * Command "limit '~d' MINTIME[-MAXTIME]", with MINTIME and MAXTIME numbers, limits files list according to file modify date (expressed as seconds since the epoch, see 'man 2 time').
 * Command "limit '~d' MINDATE[-MINDATE]", with MINDATE and MAXDATE dates as in DD/MM/YYYY, and after 1900.
 * Command "limit '-further' ..." makes 'limit' act on the current list, rather than on the full anew. 
 * Command "limit" uses new criteria:
   If invoked with '~!' it restricts to files with unique basename.
   If with '~=', to files with duplicate basename;
   if with '~^', to the first of the files with duplicate basename;
   if with '~$', to the last of the files with duplicate basename. 
 * Alias "unlimit" resets the limited list.
 * Add variable '_all_file_loaders': a space-separated list of hardcoded file loaders usable with '_file_loader'.
 * Switch -R/--recursive[=arg] has now an optional argument; overwrites (if set) or appends to (if beginning with + or |) the "_pushdir_re" variable (recursed filename extensions).
 * Introduce a "#!fim:+=" special description line to append to cached description.
 * Introduce a "#!fim:^=" special description line to prepend to cached description.
 * Introduce a "#!fim:!=" special description line to reset all variables of the cached namespace.
 * Command 'desc        "save"' functionality to save descriptions file data from the currently browsable images list.
 * Command 'desc "-append" "save"' works in append mode.
 * Command 'desc "-all" "save"' saves also all descriptions file variables.
 * Command 'desc "-nooverw" "save"' does not force overwrite.
 * To ease reproducible builds: imposing LC_ALL=C to $(YACC) and $(SORT), vim2html.pl reads SOURCE_DATE_EPOCH
 * New switch --mark-from-image-descriptions-file: read file names from a description file and use them to mark current list files.
 * Introduced alphanumeric restriction in the descriptions shebang variables: must begin with underscore or alphabetic, continue with underscore or alphanumeric.
 * Keys '(' and ')' are now bound respectively to "goto '^p'" and "goto '$p'"; that is jump to first or last page.
 * Available symkeys are now documented in a section of man fimrc.
 * Switch -k --keysym-press <keysym> to simulate press of keysym at startup.
   Keysym can be prefixed by a repetition count number.
 * New switch  -/  <pattern> as short form of of -c /<pattern>.
 * New switch --// <pattern> as short form of of -c /<pattern> with _re_search_opts='f'.
 * Tehe space key (' ') is now assigned to 'scrollforward' (earlier was 's').
 * Introduced context prepend/append shebang syntax "#!fim:^=" and "#!fim:+=" in description files.
 * Switch --read-from-stdin-elds supports now the ASCII NUL terminator (via '').
 * Switch -V (--version) prints to stdout (not anymore to stderr).
 * The -B switch is now shorthand for --background-recursive.
 * If compiled in pre-C++11 flags, -B / --background-recursive behaves as -R.
 * Switch -S is now short form of --image-descriptions-file-separator (not anymore for --sanity-check).
 * Switch -D is now short form of --load-image-descriptions-file (not anymore for --dump-default-fimrc).
 * Switch -L/--read-from-file: read an image list from file (similarly to the - switch).
 * Now caching of mipmaps is on by default; can be turned off with new variable '_cache_control'.
 * Variable "_push_pushes_dirs"; if it is 2, also push hidden files and directories; that is, ones whose names begin with a dot (.).
 * configure --with-font-magnifying-factor=FACTOR controls text magnification by an integer factor.
   If FACTOR is positive, this value is hardcoded and cannot be changed at runtime.
   If FACTOR is negative, -FACTOR is default, but can be changed at runtime.
   If FACTOR is 0 (default) a default of 1 applies, and can be changed at runtime.
   This option is meant to be used on configurations with high resolutions and small consolefonts.
 * configure --with-tmpfile specifies a new temporary directory. 
 * configure tries to detect curses/ncurses.
 * Fix: mouse movement under SDL used to trigger unnecessary screen redraws.
 * Fix: the last used image is to be evicted from the cache as last, after possibly prefetched images.
 * Fix: in configure script, the regex_t check was unnecessarily broken.
 * Fix: ./configure --disable-pcx was not properly disabling PCX format support
 * With C++11 flags, --background-recursive loads images in the background recursively (experimental, unfinished).
 * Use variable "i:_file_load_time" to store the time taken to load the file and decode the image.
 * Use variable "_use_mipmaps=2" to compute the mipmaps faster, using every fourth source pixel.  This can be a good solution for speeding up large photographs scaling.
 * Description files beginning with "#!fim:desc" (of whatever extension) can now be loaded as they were normal image files.
 * Add switch --reverse to reverse the file list.
 * Add switch --sort-mtime to sort file list according to modification time.
 * Add switch --sort-fsize to sort file list according to file size.
 * Command "list 'sort_mtime'" to sort file list according to modification time.
 * Command "list 'sort_fsize'" to sort file list according to file size.
 * Command "list 'mark' {args}" accepts now exactly what "limit {args}" does.
 * Command syntax 'list "markall"' introduced.
 * Command syntax 'list "dumpmarked"' and 'list "unmarkall"' introduced.
 * Command 'list "swap"' introduced.
 * New '_lastgotodirection' variable, with the last file goto direction.
 * Key 'Enter' now marks and goes forward or back according to variable '_lastgotodirection'.
 * Fix: the largest mipmap was not always being used.
 * Fix: -lfl linkage is not really necessary: removed it.
 * Fix: support for PPM files with 2 bytes per sample.
 * Fix: a few more checks when reading PCX files.
 * Fix: documented that switch --sanity-check terminates the program, rather than continuing.
 * Fix: when stdint.h is available use uint8_t, uint16_t, uint32_t instead of non-portable __u8, __u16, __u32
 * Fix: compilation was broken without framebuffer (FIM_WITH_NO_FRAMEBUFFER)
 * Fix: cleaned up the internal keysyms initialization code.
 * Fix: removed obsolete documentation for the "window" command, now disabled.
 * Bugfix: improve GIF error handling.
 * Bugfix: on certain framebuffer configurations part of the screen was not being redrawn.
 * Bugfix: conversion from external program was vulnerable to failure due to a missing check.
 * Bugfix: avoiding data corruption when handling %k expando.
 * Bugfix: repeating "recording 'repeat_last'" (default '.' key) by prepending a number now works.
 * Fix: configure uses `sdl-config --static-lib`.

                Version 0.5

 * -R / --recursive switch to turn on recursive push of command line specified directories
 * added --sort and --sort-basename to sort the images list
 * introduced mipmap mechanism (_use_mipmaps) for faster display/scaling of images
 * status bar customizable with _display_status_fmt and _info_fmt_str, which can be
   controlled by the use of special image variable specifiers ('expandos'):
    "%T" expando to get (and display) total memory used by the program 
    "%C" expando to get (and display) file/memory usage by image cache
    "%M" expando to get (and display) memory used by the current (displayed) image
    "%c" expando to get (and display) centering information
    "%m" expando to get (and display) current image mipmap occupation information
    "%k" expando to get (and display) current image i:_comment value
    "%?PRE?VAR?POST?" expando to get (and display) "PRE".i:VAR."POST"
    ...
 * search (and jump) on image descriptions via 'goto' and key '/'
 * when repeating search with 'repeat_last', will use last direction
 * '?' key is now assigned to backward search (goto '-//')
 * default 'C-p' key is now assigned to repeat last backward search (goto '-//')
 * image cache will remember alignment within viewport
 * jump back and forth from the last viewed image with the ' (single quote aka apostrophe)
   key and the _lastfileindex variable
 * added --load-image-descriptions-file (equivalent to 'desc' 'load') to populate 
   the i:_comment values of each loaded image file and set _caption_over_image=2
   (with it added also --image-descriptions-file-separator)
 * added the 'desc "load"' command to load a textual files comments description file
 * introduced a 'limit' command, with comment, file name, or marked file criteria
 * the '`' key is bound to toggle limit'ing to the marked files list
 * introduced 'list "mark"' and 'list "unmark"' subcommands styled as 'limit'
 * load i:_comment and i:var from description file, with forms:
   "filename comment" (to i:_comment),
   "#!fim:var=value" (to   set i:var=value on all all the files following)
   "#!fim:var="      (to unset i:var=value on all all the files following)
   "filename #!fim:=" (to i:_comment from the value read last)
   "filename #!fim:+comment" (similar, but will append the new comment)
   "filename #!fim:^comment" (similar, but will prepend the new comment)
   "filename #!fim:s/f/t" (similar, but replace string f with string t)
 * EXIF tags will be read with libexif and become i:EXIF_-prefixed variables
 * if _want_exif_orientation is set, images will be reoriented according to EXIF
   metadata (i:__exif_orientation, i:__exif_mirrored, i:__exif_flipped).
 * the 'help' command will search also in fim command options
 * will optionally use C++11 constructs with ./configure --enable-cxx11 (no user level impact)
 * scaling image code faster (thanks to __restrict__ pointers)
 * customizable SDL window caption line with _want_wm_caption_status
 * BMP format support is now optional
 * PCX format support (optional)
 * changed meaning of variable _ignorecase: now it affects autocommands
 * introduced variable _re_search_opts affecting regexp-based search
 * default key 'r' is bound to 'rotate90', key 'R' to 'rotate270'
 * can be invoked without stdin; e.g. from an X menu
 * added "display 'resize'" to resize the SDL window, optionally to the image size
 * default SDL mode is windowed now
 * by default, the 'C-w' key will resize the SDL window to the original image size
 * by default, the 'W' key will resize the SDL window to the image size,
   and added an --autowindow switch to adapt window size to picture size
 * the 'help' command will search in help items if argument starts with /
 * special variable i:* expanding to all the variable name/value pairs of the current image
 * opening image files in archives (e.g. CBZ,CBR,RAR,TAR,TGZ,TBZ,7Z,ISO,...)
   with libarchive (experimental)
 * JPEG-2000 file support via JasPer (experimental)
 * added a ':- INTEGER' syntax, so one can specify the file in the list counting from the end
 * added an _archive_files variable to specify which file name types specify archives
 * added a 'list "pushdirr"' command, working like "pushdir" but recursively
 * the _fbfont variable will contain the current console font file string
 * mirror/flip are now being applied with respect to the viewport borders
 * stat() checking of files on load can be disabled with _push_checks
 * added --no-stat-push to set _push_checks=0 before initialization
 * added the _caption_over_image variable (which is 0 unless --load-image-descriptions-file)
 * 'Pause' and 'Menu' keys are now available in SDL (-o sdl) mode
 * added  'list' 'marked'  to show the list of marked files
 * key 'Del' bound to pop (delete) the current image from the list
 * i:_file loader will store the used loader string
 * switch --offset accepts a range now (using the new _open_offset_retry variable)
 * if an image has been opened with an offset, i:_open_offset will be set accordingly
 * variable i:pagecount is now replaced by i:pages
 * put aside (disabled) the v: b: and w: namespaces until they make more sense
 * panning on mouse movement in SDL mode
 * `make fim' goal has been deleted
 * changed librsb library detection: now it's e.g.:
   LIBS="`librsb-config  --ldflags --extra_libs` " CXXFLAGS="`librsb-config --cflags` "\
   ./configure --enable-matrices-rendering
 * bugfix: in some situations fim -o fb was not clearing the screen before drawing the image
 * bugfix in the "list 'remove'" internals
 * --binary=1/--binary=24 will not pad tiny renderings to _preferred_rendering_width pixels
 * fix: corrected the quiet mode (-q) to be quieter
 * fix: no zlib.h build time dependency (this will be reintroduced in the future)

                Version 0.4

 * changed --random semantics and introduced --random-no-seed switch
 * customizable status bar file info string
 * introduced --as-text to render printable bytes as text
 * key r is bound to 'rotate90', key R to 'rotate270'
 * bug fixes for the g: namespace, SDL/X mode, "list 'pop'" command, 
   the --offset option, 'ascale' and rotation, documentation.

                Version 0.4-beta

 * interface to the GraphicsMagic library (more graphics formats supported)
 * introduced bitwise AND and OR operators
 * support for rendering "matrix market" numerical matrix files (with librsb)
 * X mode not anymore default in aalib, available at option 
 * libjpeg usage fixes
 * libpng usage fixes (support for PNG_LIBPNG_VER>=10209)
 * documentation improvements (e.g.: fim man page is auto-generated)
 * "imlib2" X-based output device support 
 * "sdl" output device improvements (fullscreen/mouse/windowed options, I/O, ..)
 * more default consolefont options (e.g.: hardcoded consolefonts support)
 * configure option to disable the fim history file
 * improvements to scale, goto, other commands
 * improved directories reading
 * introduced --no-commandline, --no-internal-config switches
 * aggregated some commands for clarity
 * output console can be disabled at configure time
 * important fbdev bug fixes 
 * autocompletion of variable identifiers

                Version 0.3

 * minor strchr compilation problem on some systems
 * better consolefonts support  
 * much better SDL support (different color modes)
 * 'negate' feature
 * -S, or 'sanity-check' switch [changed meaning in v0.6]

               Version 0.3-beta-prerelease

 * auto-generated documentation: more consistency 
 * grammar specification, in man fimrc
 * internal commands,variables,autocommands  reference man page, in man fimrc
 * better internal help mechanisms
 * more control (resolution change,windowed mode) in experimental sdl mode
 * new commands (pread,reverse,shuffle,...) 
 * (temporarily) disabled internal windows splitting 
 * pushing files from a directory
 * several minor and major bugfixes

                Version 0.3-beta

 * full         support for AAlib (ASCII-art rendering) (-o aa)
 * experimental support for SDLlib (Simple Directmedia Layer) (-o sdl) (X!)
 * experimental PDF, PS, DJVU file support
 * history file support (~/.fim_history)
 * seamless caching and prefetching integration
 * viewing of any type files as bitmaps (unset bits black, set bits white)
 * viewing of any type files as pixmaps (as RGB triples)
 * framebuffer driver now can be disabled at compile time
 * colors inversion: saves a significant fraction of power when viewing documents 

                Version 0.3-alpha

 * experimental support for AAlib (ASCII-art rendering) (-t)
 * reading image files (-i) and scripts (-p) from stdin
 * runs on the powerpc architecure
 * rewritten from scratch the debug console, now buffered and with scrolling
 * achieved speedup in magnifying pictures
 * achieved speedup in displaying dithered images
 * smarter quoting rules (looser quote checking) when "push"ing files
 * dumping to file execution logs as executable scripts (-W/--write-scriptout)
 * implemented regular expressions matching operator (=~)
 * new default key bindings for split windows control
 * could be compiled with no readline library (--disable-readline)

                Version 0.2
 
 * internal windowing (with splitting, resizing, swapping) support
 * .xcf, .fig, .dia, .svg files now viewable via wrapper calls
 * introduced interactive command iteration ( in the [n]<command key> form )
 * fim will try to run under screen and over ssh now
 * custom framebuffer device, fonts and gamma are supported
 * enriched compile-time options via the ./configure script
 * vim-styled variable scoping g:,i:,v:,w: (local variables)
 * eradicated some bugs
 * introduced new variables, commands

                Version 0.2-alpha
 
 * first windowing functionalities
 * bugs and subtle flaws handling
 * introduced new variables, commands

                Version 0.1

 * regular expressions for filtering the viewed image list
 * vim-like autocommands
 * command line autocompletion
 * command line history
 * completely customizable key bindings
 * external/internal scriptability