Minor improvements to font rendering.
Added classes for transformation matrices and matrix stacks.
// I realized that the current render mechanism is nicely encapsulated but rather ineffective due to overmuch state changes in intermediate mode. The encapsulation was designed to easily switch the rendering to OpenGL >=3 or ES someday, but I realized that thats quiet the same and way more efficient than the current approach. I'll rewrite the code to use core openGL 3.3 only and hope my shitty integrated GPU goes with me... :/