flipped gl qc rendertargets to logically be top-down. the joys of weird matricies is a sight to behold.
try to fix threading dependency on recent versions of windows.
break some other related stuff.
git-svn-id: https://svn.code.sf.net/p/fteqw/code/trunk@4768 fc73d0e0-1445-4013-8a0c-d673dee63da5
unified image loading code a little between renderers.
support switching worldmodel in csqc. also associated bugfixes.
git-svn-id: https://svn.code.sf.net/p/fteqw/code/trunk@4758 fc73d0e0-1445-4013-8a0c-d673dee63da5