Hooks for ItemFrame and ArmorStand

[toddharrison]

Cancelable hooks need to be added for ItemFrame and ArmorStand entity events. Specifically:

• When ArmorStands are destroyed
• When Items are placed, removed or replaced on ArmorStands
• When items are removed from an ItemFrame
• When items are rotated in an ItemFrame (can currently be handled with the RightClickOnEntity hook)

[toddharrison]

In the current ArmorStandModifyHook I need a way of getting the targeted ArmorStand.