Improve events for new inventory features. Adds BUKKIT-3859

This commit brings the InventoryClickEvent up to date with the new Minecraft
changes in 1.5.

InventoryDragEvent (thanks to @YLivay for his PR) is added to represent the
new "dragging" or "painting" functionality, where if you hold an itemstack and
click-drag over several slots, the items will be split evenly (left click) or
1 each (right click).

The ClickType enum is used to represent what the client did to trigger the
event.

The InventoryAction enum is reserved for future expansion, but will be used to
indicate the approximate result of the action.

Additionally, handling of creative inventory editing is improved with the new
InventoryCreativeEvent, and handling of numberkey presses is also improved
within InventoryClickEvent and CraftItemEvent.

Also, cancelling a creative click now displays properly on the client.

Adresses BUKKIT-3692, BUKKIT-4035, BUKKIT-3859 (new 1.5 events),
BUKKIT-2659, BUKKIT-3043, BUKKIT-2659, and BUKKIT-2897 (creative click events).
Consider full team display name. Fixes BUKKIT-4186

Through a miscalculation, team display names were being created via
command ignoring the first word in the submitted display names.
Add PlayerBookEditEvent.  Adds BUKKIT-1995
Event related to book & quill and written book items.
Updated version to 1.5.2-R1.0 in pom.xml for RB.
Updated version to 1.5.2-R1.1-SNAPSHOT for development towards next release.
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 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.