upgraded rtlights format to have separate ambient, diffuse, and specular intensity...

upgraded rtlights format to have separate ambient, diffuse, and specular intensity scales, and also coronasize, this also allows corona-only lights by setting all scales to 0, and added normalmode/realtimemode flags so that lights can appear in normal mode, not just realtime mode (primarily useful for adding corona effects to a normal level)
added ambient light support to RenderLighting (non-bumpmapped diffuse)
some dlights now use ambientscale (this has not been exposed as a qc extension yet, qc lights remain the same)

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@4753 d7cf8633-e32d-0410-b094-e92efae38249