There is an OpenGL error (1282) invalid operation that is getting
caught when switching to the imagescene. This needs to get fixed
and then hopefully the whole thing will work.
MyBuiltinTexturedScene (number 7) displays a cube that loads its
faces from a hard-coded texture. Mipmaping is supported. Just use
the XXX_MIPMAP_XXX Min/Mag filters to use it. TODO next is
combining lighting and textures and then up after that is shadows.
I may just do lighting and shadows before lighting, shadows, and
textures.