VRM now has a clean design, these the main changes, in order of appearance :):
* Add a license and a copyright block
* Split out Projection from rendering so we can support different projections
* Add back-face culling
* Decouple the rendering process from the output writing, so we can support
multiple output formats
* We now have a Renderer class witch encapsulates the rendering process
Signed-off-by: Antonio Ospite <ospite@studenti.unina.it>