view/renderer handling of surface shaders

[James W. W. <os...@jw...>]

I'm trying to figure out why the Interactive Renderer does the wrong  
thing with the test file "texture-interference.3dmf" that I recently  
committed.  I think it has to do with the fact that TQ3ViewStackItem  
has two surface shader members, shaderSurface and  
attributeSurfaceShader.  Anyone know why?  It seems crazy.  But maybe  
I'm just tired.