Extended the basic 3D function API and ensured that lighting and fog in fact
do work. Also implemented the missing math functions provided by GM:S such as
clamp and dot_product.

Committer: Robert B. Colton

modified: Graphics_Systems/OpenGL/GSd3d.cpp
modified: Graphics_Systems/OpenGL/GSd3d.h
modified: Universal_System/mathnc.cpp
modified: Universal_System/mathnc.h