refactor and extend with colors
* add color buffer
* add vertex info for colors
* rework debug
* nicer camera
* add some inline code documentation
readme
Merge branch 'feature/refactor-v5' into develop
v6 changes: css/viewport, cube, fps counter
* add mesh for cube
* care for frames per second handling
* add fps counter
* add missing shader parameters for color
* nicer demo page