Scenegraph rewrite

[joevenzon]

Using render to texture + shader to bake the car texture. But for this I need to be able to load the custom shader and render the texture(outside of the scenegraph). The good thing is that I'll need this functionality for the dynamic sky anyway.

If their card can't run shaders, it's unlikely to support render to texture (framebuffer objects).

There's already functionality to render to textures (this is used by shadows, dynamic reflections, etc), although currently it's set up to happen each frame... if you need to bake something out once that'd have to be a special case.