Merge pull request #4 from Katalliaan/master

Spells Dev
Pigmen experiment. Drops changed from gold to silver. Goal is to make
them use silver in the future
Same as before. Pigmen somehow carry both their vanilla sword and the
Rubedo sword in the same hand.
Narrowed down causes of issue: LivingSpawnEvent and EntityJoinWorldEvent
fire BEFORE mobs get their equipment; Rubedo tools don't render when
held by mobs (custom items do - could see them holding copper bars just
fine); when dropped, Rubedo tools can be at 0 durability but not broken
(possibly fixable through LivingDropsEvent).
Removed some debug code, unregistered LivingSpawnEventHandler until a
solution can be found
Merge pull request #5 from Katalliaan/spells-dev

Moved gold-to-silver drop changes into master