LambertLit test now uses sm2 shaders when UBO not defined.

Provides more test coverage for shaders compiled from dx9 HLSL.
Fixes for sm1/2/3 VS/PS linking.
Fixed constant table not being declared when c0 was not a valid constant
register. This can happen when register(cX) is used in HLSL.
Build fix for assimp on visual studio 11.
Support some of the operand modifiers on dx9 shaders.