Needs names for the UI components to distinguish them, and probably stacking vertically for easier comparison.

- moved demo stuff to separate file
- created two separate examples for gl2 and gl3
- initial stab at OGL 3.2 core profile back-end (currently twice as
slows as 2.0)
- API change: glBeginFrame() takes view witdth and height as input
- added FPS counter to demo