Lots of changes... Sorta...

4th rewrite of how tracks are represented, I'm pretty confident this
will be the last complete rewrite. That thing I said about the tile
entity controlling rotation, I lied. Rotation is now handled by the
TrackManager class. BlockTrackBase and TileEntityTrackBase are now the
classes representing tracks. All rendering methods switched over to
using BlockTrackBase as reference instead of the tile entity.
GuiHammerOverlay changed, displays more information and stops displaying
when the F3 debug screen is being displayed.
Known Issues:
Tracks have issues with rotating, these include: all tracks rotating to
face the same direction, sloped tracks only ever facing one direction.
This is believed to be caused by the static nature of the TrackManager,
will be looked at further.
Hammer doesn't rotate or change the style of tracks at the moment, this
was disabled to allow for the switch to
BlockTrackBase/TileEntityTrackBase, will be re-enabled when kinks get
ironed-out.
Track rendering is still broken for some tracks, this will be fixed by
simply adjusting the rendering offsets of the track blocks.