- upload only the dynamic AABB subtree using glBufferSubData
- change internal raytracing stack limit from 16 to 32
- update shadowmap AABB tree after R_SetupFrame for proper frame interpolation
This should be less of a drag on the playsim than having each light a separate actor. A quick check with ZDCMP2 showed that the light processing time was reduced to 1/3rd from 0.5 ms to 0.17 ms per tic.
It's also one native actor class less.
* split gl_shadowmap.cpp into a GL dependent and an API independent part.
* gl_drawinfo must be kept around for the HUD sprite because it connects the renderer with the hardware indpendent part of the engine.
