LICE: added LICE_BitmapCmpEx() for comparing ignoring bitmask -- from 97ae08bd
lice_gif_write: allow writing less than 256 colors to file when not needed -- from 4f4fe41a
LICE_palette: LICE_BuildOctreeForAlpha/Diff return pixel-diff count rather than leaf count
lice_gif_write: avoid generating a 32kb lookup table when the number of pixels being generated is less than 40,000