Reworked player speed calculations
Fixed debug image rendering in the wrong order
Added frustum culling to faces
Optimised frustum culling (fix #19)
Packaged interpolation into a function
Made triangles not attempt to draw if they are offscreen.
Fixed frustum culling not working properly
Cleaned up a bit of debugging code
Added vector classes to bounding sphere calculations
Fixed broken bounding sphere calculations

- didn't work

 - added matrix inversion
 - does work