improved TraceLine in chase.c to be more generally useful (should move it to another...

improved TraceLine in chase.c to be more generally useful (should move it to another file, though)
error checking in qmalloc/qfree
expanded COM_LoadFile max filename length from 32 to 1024
improved COM_LoadFile error messages
added COM_ToLowerString and COM_ToUpperString
.zym model support (not quite complete, in development)
unfinished transition to hardware model transforms (not used yet)
changed polylists to draw 5+ point polygons as GL_POLYGON instead of GL_TRIANGLE_FAN (I thought I had reverted to GL_POLYGON a long time ago... strange) for a minor speedup
new explosion effect (no particles)
reverted to lightmapped dynamic lighting effects (vertex hybrid still available as r_dlightmaps 0)
extreme speed improvements in which wall polygons are lit
minor optimization to lightmap building (memset to clear blocklights)
added and disabled texture caching to disk (it turned out to be a slowdown and a massive waste of space, but kept in source form incase it is ever useful)
much improved missing QC function errors (most notably think)
partial redesign of the skin colormapping engine (not used yet)
more consistent light falloff on different objects
created and scrapped a new particle explosion effect (way too fillrate intensive), superseded by the new explosion effect
only dynamically lights smoke and blood particles unless r_dynamicparticles is 2
possible fix for alt-tab bug in NVidia drivers (from Dabb)

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@152 d7cf8633-e32d-0410-b094-e92efae38249