More fine-grained dependency selection

Update cmake

Add OpenSlide support

Multiple file - limit unset loops to 1

Don't loop non-animated PNGs in video mode

Async terminal writing; 8 bit mode

Most notable: better read iTerm2 color.

Bump version. Most notable: support of iTerm2 graphics

Bump version. Most notable: Kitty terminal graphics, improved transpa…

…rency, quarter blocks

Bump version number. Fix -f, special-case JPEG