Add BlockCake for diff visibility.
Fire FoodLevelChangeEvent when eating cake. Fixes BUKKIT-2242
Call ItemDeathEvent when an Item is killed. Adds BUKKIT-1900

This plugs a hole in a plugin's ability to track the lifecycle of Item entities, for example, the flag in a capture-the-flag game.
The method in CraftEventFactory performs a best-guess estimation of the DamageCause from the death. It may be prudent to merge this code and the logic in handleEntityDamageEvent sometime in the future.