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 1.6 PlaySound command. Fixes BUKKIT-4489
Add 1.6 SpreadPlayers command. Fixes BUKKIT-4508
Add 1.6 effect clear functionality. Fixes BUKKIT-4473
Account for relative coordinates in PlaySound. Fixes BUKKIT-4639
Add leash API.  Adds BUKKIT-4459 and BUKKIT-4583
Use player as point of reference for min volume. Fixes BUKKIT-4640

When the minimum volume is being used because the distance is over a
threshold, the unit vector delta should be added to the player's
location, instead of where the command specified location.

This change makes the player's location the point of reference for
playing sounds when distance to volume scale is lower than minimum
specified volume.
Pulling all pending Bukkit-JavaDoc changes
Updated version to 1.6.2-R0.1 in pom.xml for Beta.
Updated version to 1.6.2-R0.2-SNAPSHOT for development towards next release.
Implement command tab completion in the console. Adds BUKKIT-4168

To accomplish this 2 changes to Bukkit were required:
- the player check in Command.tabComplete() had to be removed
- the SimpleCommandMap prepends the / only for players
fixed a CCE in Command.tabComplete() introduced in the last commit