Basic demo of terrain

First scratch of the background terrain
Small terrain generation update

Changed some parameters of the fractal noise and changed quads to
triangles..
Basic Lighting (diffuse + specular)

Implemented some basis lighting, but still needs to be updates to the
phong model. Other issue is the performance which needs to be optimized.
Furthermore, terrain generation needs some additional improvements (e.g.
less hilly).
..
Implemented phong model

Updated Lighting to phong model and some tweaks to the terrain
generation. Still, need to increase speed though.
Some improvement in rendering

Some fixes to speed up rendering of the background
Optimized performance

Nu worden alleen de driehoekjes getekend en de bijbehorende berekeningen
gedaan wanneer het in beeld is.
Some refacoring

aparte klasse voor de terrain generatie
thumbs file has to be commited
Merged?

achtergrond wordt nog niet getekend.