Don't allocate interpolation data for RandomRotationRange when not needed
Hope this commit doesn't break some visuals; i'm not 100% sure.
Some particle files may rely on this behavior to look as intended.
This untangles some of the gigantic kitchen sink headers
in an attempt to split things into smaller files.
Also don't include gl.h, glext.h, windows.h,
and other such nonsense *everywhere*.
Lots of cleanups on the way too. More dead/unused code removal.
Remove incrFlag(), decrFlag() Lua functions.
GL_CULL_FACE is effectively always disabled, except for quad strip
rendering, and keeping GL_CULL_FACE disabled there does not seem
to cause any visual artifacts.
Instead, it enhances skeletal animation possibilities
(e.g. flipping bone strips over without it disappearing)
