change isValid method to throw an IllegalStateException
throw exception if accessing GenericsLib before its enabled
add comments,

throw exception if spawning disposed entity

remove redundant code
update GlobalRegionManager type comment
add callBukkit method

callBukkit method calls a Bukkit event on the Bukkit event manager, then on the generics manager instance.
add IPlayerOwnable interface
use GenericsLib event manager to call bukkit events

update comments

remove obsolete or unused events