Fixes BUKKIT-589: if you call damage on an instance of EnderDragon, no damage
is done.
Reason for bug: damage calls Entity.damageEntity. But EntityComplex
overrides damageEntity to do nothing.
Fix: CraftComplexLiving should call EntityComplex.e instead of
Entity.damageEntity. e is the method that actually does damage to an
instance of EntityComplex.
