* All IPhysShapes now expose a property to get the local AABB.
* Removed IMapChunk. It's internal, we only have 1 implementation in the engine, no need for abstraction, and removing it helps perf.
* Cleaned up issues in MapChunk file.
* Encapsulate _tiles access inside MapChunk.
* Remove IEnumerable<TileRef> from MapChunk.
* Remove CollidesWithChunk
* Move CalcWorldAABB and RegenerateCollision from MapChunk to MapGrid.
Remove MapChunk.GridId.
* Removed MapChunk.GetAllTiles
* Removed the terrible mocked unit tests.
* Moved the GetTileRef functions from MapChunk to MapGrid.
* Add an event raised on MapChunk when a tile is modified.
Completely remove the IMapGrid dependency from MapChunk.
* Fix bug where you cannot change the tile damage of a tile.
