Things we still need to work on in the library
+ Finish apidox
: the code generation macros in kmime_headers.h are a problem for doxygen
+ Use KDateTime::toString() as much as possible in DateFormatter class.
If KDateTime ever supports fancy format, we should be able to replace
DateFormatter completely with KDateTime::toString().
+ Lots of methods we might want to de-inline
+ Remove extra namespaces. probably only KMime namespace needed.
+ There are also methods, eg. in kmime_header_parsing.h, which don't need to
be part of the public API
+ More tests and unit-tests