When shadows and light combine

Now it's not just primitives and smooth shading! Multitexturing is part of OpenGL since 1.2.1 specification and allows direct textures combining. Putting the shadow map into a separate texture unit (with glActiveTexture) permit us to spread it on our already textured polygons.

I don't know if this is the most performant way to achieve a correct result, but it works fine! =)