Separate drawing of water polys in Quake 2.
Changed non-multitexture drawinf of Quake 2 worls surfaces to draw them immediately.
Removed now unused performance conter.
Changed non-multitexture drawing of Quake 2 world surfaces to blend lightmaps immediately.
Merged some common code of Quake 2 surface drawing.
Use one method to also draw Quake 2 alpha surfaces.
Draw Quake 2 world surfaces on back-end.
Separate surface type for drawing Quake 2 skybox.
All alpha surfaces must be rendered with world matrix.