Log Message:
sdl12-compat: updated to 1.2.68

1.2.68

Corrected SDL_SetPalette's return value.
Fixes to headers to help compiling apps against sdl12-compat
Sync dr_mp3 with upstream.
Fixes to SDL_LoadWAV_RW
Reworked screen surface implementation to work more like real SDL-1.2
Fixed blank screens in Mark of the Ninja and Trine
Fixes to mouse tracking in relative mode when scaling
Add quirk to clamp video bitdepth, which fixes Hyperspace Delivery Boy