rewrote colormapping handling to store colormap_pantscolor and colormap_shirtcolor...

rewrote colormapping handling to store colormap_pantscolor and colormap_shirtcolor in entity_render_t rather than having the annoying palette lookups in the renderer, while doing this I removed support for fullbright rendering of colormap colors 14 and 15 (this shouldn't really affect anyone, stock quake did not even let you use these colors, and they're ugly colors anyway :)
rewrote portions of surface renderer again, to improve readability and overbright handling, this shouldn't change anything visually

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@5720 d7cf8633-e32d-0410-b094-e92efae38249