- Ztransp material didn't raytrace at all (now just traces it entirely,
remember too set the transp depth for it)
- tramsparent material reflected wrong in mirror material, due to
specular being added without alpha.
- Cleaned up some code to improve raytrace speed some. The old conventions
from before the AA recode were still there, this allowed coherence for
octree traversal. Current AA doesn't allow this anymore.
Added is improved check for 'first hit' on shadow render, per lamp this
now is stored
All in all, render with ray trace improved about 10-15%.