Correct the small (10^-4) jittering due to kernel aliasing in Lanczos mode.
Add support for compressed input images.
Improve the quality of background subtraction, and make it multithreaded.
Add support for PV/DV parameters according to the final WCS documents
(when they are released!).
Add "Drizzle-like" RESAMPLING_TYPE (square top-hat with width < 1 pixel).