tweak rtlights a bit, to not bug out on The Waste's decals.
use compatibility glsl in order to get ftransform working for consistent vertex coords (still uses core if there's no fixed function stuff). this fixes z-fighting issues with rtlights.
Rework punchangles for greater compatibility.
git-svn-id: https://svn.code.sf.net/p/fteqw/code/trunk@5059 fc73d0e0-1445-4013-8a0c-d673dee63da5
