Support conditional expressions in shader effect XML files.
Consolidate fixed-function model rendering into the shader system.
Remove lots of now-obsolete renderer code.
Move shader defines from std::map to new class with interned data, for
performance.
Move texture from model into material.
Alleviate singletonitis.
Remove obsolete lodbias setting.
Remove unused terrain shadow transparency.
This was SVN commit r11423.
