Clean up matrix math in anticipation of putting matrices in uniforms

Remove matrix math from InitializeGL; set it in DrawFrame
    generate frustum fresh each time

Frustum and Scene Manipulator were using different FOV, use the same one

Remove some code that isn't used in shader

Also forgot to commit some of model refactorization
    include drawable.h
    compile model.cpp in Makefile
    delete model vertices
Add Apache license