Rebase onto master for API changes.

Add hopper, ActivatorRail, Fix incorrect NetherOre  implementation.  NetherRack is now smeltable into Brick.
Redstone Comparator, TNT Minecart
Minecart Protocol changes, WindowOpen Codec Changes
Added RedstoneComparable to help with getting comparable strength of blocks that are attached to comparators.

Signed-off-by: Sleaker <sleaker@gmail.com>