Major dynaterrain update

+Architecture review
+DynamicPlanet class now fully works
+class NzTerrainQuadTree has been renamed in NzDynaTerrainQuadTreeBase
the quadtree class is the same for terrain and planet, one method only
has been specialized to avoid bloating the entire architecture
+Major code cleanup
+Increased code readability/maintainability (still a lot to do though)

Note : Due to buggy behavior of github::windows (encoding maybe?), some
files without changes have been committed