Add: BlockGrow trigger (eg. when wheat, sugarcane, cactus, etc grows)
Add: "named chest" support now uses InventoryHolder to also support names for dispenser, brewing stand, etc.
Fix: some OtherDrops spawned creatures not working.  Fixes #245.
Minor: allow lowercase aliased triggers to work
Fix: reset all "dropFor" variables so only the correct listeners are loaded after a "reload" command
Dev: variable parsing split into a seperate class, no functional changes
Minor: fix typo in log message