Cleaned up Tiles and APIs.

Core will no longer host all external mod APIs. Many have been removed, in fact all except the Buildcraft Wrench and a few CoFH API interfaces. The RF API was updated resulting in only a single meaningful change.

Tile Entity interfaces were moved to their own API package, and I imported a couple new ones from CoFH and created a few more as well as tweaking some of my own.

Moved IFacedTile out of TileEntityGeneric. Added FacedTileHelper to cover common use cases, currently there are two.

Paved the ground work for dismantleable tiles, though that still needs work.

So many changes, a version bump was required. This is now 2.1.2.