ItemUtil has a requirement of being only 1 of each stack, instead of
standard amounts.
Updated the few missing official Skins for HeadDrops.
Also added wolves.
Use BlockEvent for betterPhysics. Should catch all.
Allow Sentry Guns to be disabled when powered
Fixed BetterPhysics.
Revert "Allow Sentry Guns to be disabled when powered"

This reverts commit d8aca2a6d008e42194a711c5bbfe44b92740497a.
Fix snow distance calculations.
Improved Sentry Gun

* Allow the Sentry Gun to be turned off when powered
* The Sentry Gun will now look for the highest nonsolid block similarly to the Creature Spawner before firing arrows
Made getting access to CraftBook components far easier to improve usability as an API
Fixed BetterPistons up/down signs support.
Stop non-rideable carts disappearing.
Tweaked HiddenSwitch to use the new system. Fixed a few permission
messages not being localizable.
Added jukebox pull support to pipes.
Fixed XPStorer error.
Print a message if chunk anchor fails, and print the error if in debug
mode. Using this debug mode error idea for odd errors may be useful.
Update to latest bukkit.
Tweaked HiddenSwitch.
Move variables to a seperate mechanic.
Added usage to Variable commands.
Added CraftBook 3.8 Beta 2 Changelog.