* handle brightmaps in the main shader instead of keeping separate instances around.
* added detail and glow layers from Raze.
* fixed material setup which could not guarantee that everything was initialized correctly.
* for warped textures, warp all layers. With this brightmaps finally work on warped textures.
Note: Vulkan reports a "device lost" error with this which still needs to be investigated.
This builtin function no longer exists outside of backwards compatible GLSL compilers so it needs to be remapped to 'texture' so that user shaders still using it can compile.
