List of changes:
- Modified bvh class to handle 2D and 3D as a template
- Changes in Rect2, Vector2, Vector3 interface to uniformize template
calls
- New option in Project Settings to enable BVH for 2D Physics (enabled
by default like in 3D)
Complete rewrite of spatial partitioning using a bounding volume hierarchy rather than octree.
Switchable in project settings between using octree or BVH for rendering and physics.