Mob Drop Stopper

Will now only block / replace drops by mobs (monster or animal) as intended, but not other entities (fixes a problem with player inventories being edited on death - as well as some other possible problems not initially foreseen).

Will actually edit drops from any entity other than a player or vehicle (mob or not); this is intended and required for working with modded mobs on Cauldron (its original purpose).

(Note: This has been tested on Minecraft 1.9.2, 1.8.7, 1.7.10, and 1.6.4, it probably works with version in between at least, but has not been tested specifically on other version; has been tested with Craftbukkit and Cauldron, but not Spigot.)