Added Skulls / Minor bugfix for Ender Frame Portals

*Updated to allow access to TileEntities information since this was required to
 render the skulls properly
*Added skulls and did appropriate work for all north directions.
*Not all rotations of skulls are working since this is rotating a 3D block which
 hasn't been done yet
*Screenshot at: http://i.imgur.com/q0aCI.jpg

Also minor update to ensure that Ender Frame Portals with inserted Ender Eye
will render properly