Added light to graphics
added geometry key to light
updated cow
removed some functions from io that were breaking the local build
Added Tangent to snowmew render
added full materials to shader
Cleaned up ambient shader
cleanup texture setup in defered pipeline
added point shader
changed depth to a texture and normlize normal
added basic point light
Added ks to point light
added dynamic lights
Use the lighting buffer
added directional light support to the shader
Added sun to demo-cubes
Merge pull request #8 from csherratt/lighting

Added lighting support