Update spawnEvent.java

Updating event checking which will both ensure that the mob is in the prescribed world/s and is a natural spawn
Update MobSpawn.java

Updated Mobspawn and took out every reference to the task system that used to be in it.
Update Config.java

Updated default config file to properly set up the world section of the config file.
Did a little error checking and prioritization of event handling. Git
master branch now can be exported as a jar and works.
Added new Complex Entity Constructors with Potion Effect parameters