split and play

fix gifs with inconsistent frame sizes breaking in webp encode

cleanup, update libs and support proper gif/webp animation

better webp lib, webp/gif animation support, various improvements

integration tests, better patterns for outputs, help subcommand

xcf (decode-only), dng (decode-only), better sniffing, --input.codec …

fixed xbm, added xpm

heif/heic, multiple input/output, pattern/batching, cleanup, multithr…

effects and pcx,svg,farbfeld and updates

pnm, psd, tga, xbm, qoi