Add Light class files
Revert to using lookAt for lights
Add second light and looping for multiple lights
Begin to use array textures so that the frag shader can access the depthmap of all lights
also, rudimentary multi-light shadow casting
Clamp visibility to 0.2-1.0
Merge branch 'lighting' of https://github.com/FastQuake/E410 into lighting
All the shitcode is gone.

Conflicts:
	Graphics/Light.cpp
	Graphics/RenderManager.cpp
	Graphics/RenderManager.hpp
	data/shaders/fragment.glsl
	data/shaders/vertex.glsl
	main.cpp