G3D Innovation Engine Code

A couple weeks ago I merged a fix for Macs. The MacOS implementation of
glLinkShader does not allow uniforms to be passed as arguments in
functions, so I moved the uniform to a central file to be used as a
global variable. This is causing namespace collisions with another
variable in the ParticleShader files. This is a quick fix. We can come
back to it at later date.