Added placement and interact handling for fence gates and trapdoors.
Fixed ShapedRecipe matching (fixes #465).
Fixed hoe interaction with coarse dirt and podzol.
Fire PlayerItemHeldEvent when players switch their held item.
Implemented remote console (rcon) support (closes #451).
Added support for player and mob heads.

Includes dandling for the skull item, block, and tile entity, as well as
lookup of profiles based on username for Bukkit support.
Implemented wall and standing banners.

Covers placement, tile entities, serialization, and sending the banners to
the client. Does not include crafting.
Add basic random blocks tick
Add BlockCocoa, move random as protected static field to BlockType
Add BlockCrops
Add BlockMushroom
Add BlockSapling
Add BlockStem, remove BlockMelonStem and BlockPumpkinStem
Add BlockNetherWart
Add BlockSoil
Call BlockFadeEvent when soil turns back to dirt
Fix typo in BlockMushroom
Add BlockGrass (grass spread and decay)
Fix equality checks
Use an active chunks set for the block ticking