Avoid CME when lightning strikes by making a copy. Fixes BUKKIT-2055
Don't tick chunks or entities on chunks that are queued for unload.

Treat chunks in the unload queue as if they are already unloaded to prevent
processing on them removing them from the unload queue and leaking.
Add AABBPool for diff visibility
Fix bounding box pool to use a dynamic cache size

Also changed insane array copy routine. This should reduce server lag
spikes that occur periodically.
Fixed PlayerManager ConcurrentModificationExceptions. Fixes BUKKIT-1972
Don't use Packet56 and clear client cache on world changes.
Put forceChunkLoad back to its original value.
Cease execution if block is AIR. Fixes BUKKIT-2104
Add Vec3DPool for diff visibility
Fix Vec3DPool; don't pool objects indefinitely or O(n^2) clear()
Fire EntityDeathEvent for pigs. Fixes BUKKIT-2100
Add BlockTripwire and BlockTripwireHook from mc-dev for diff visibility.
Fire events for tripwire and hooks.
Fix "moved too quickly" detection.
Don't rotate ShapedRecipes. Fixes BUKKIT-1334

ShapedRecipe's getShape() always returns a 90deg rotated shape of the original shape, this commit fixes it.
Fix dispenser removing data from items. Fixes BUKKIT-2045
Pistons no longer extend before they are pistons. Fixes BUKKIT-1999
Don't force chunks to load again, causes chunk leaks with multiworld.
Tripwire isn't redstone, only fire interact events.
Implement new deprecated warning state configuration option