AnvilUpdateEvent & PlayerRepairEvent

* Added AT for ContainerRepair.stackSizeToBeUsedInRepair (Now public)
* Added ability to AnvilUpdateEvent to alter stackSizeToBeUsedInRepair (vanilla behavior is now reproducable)
* Added PlayerRepairEvent, fired when the player removes an ItemStack from the output slot of ContainerRepair, and allows the chance to damage the anvil to be altered (multiplier float).