updated documents for 0.97.0 changes so far.
image.c: Accept type 3 (uncompressed grayscale) TGA files.
Bump MAX_MODELS/MAX_MOD_KNOWN to 4096
add note about the XMP_MAX_FRAMESIZE constant change to changelog.
bump version to 4.7.0
Fix xmp_start_player unmuting regression from 4.5.0.
Host_Map_f: replace Q_strrchr and Q_strcmp with libc calls
ice_unpack: make variadic macro debug() work with old gcc versions