Update Bukkit for Minecraft 1.6.1
Add scale health display API. Adds BUKKIT-4432
Update Bukkit for Minecraft 1.6.2
Add Horse API. Adds BUKKIT-4424

API has been added to interface with Horses and to modify their inventories. A new event, HorseJumpEvent, has been added to be fired whenever a horse jumps.

This commit fixes BUKKIT-4393.
Minecraft spec has changed and we're required to follow. We now build with Java 6.
Add API to control scaled health. Adds BUKKIT-4590
Add new methods for altering permissions in bulk. Adds BUKKIT-426

Remove duplicate permissions checks.
Add some unit tests for permissions and the add/remove methods of PermissionAttachment.