NearestAttackableTarget search adjustments
Instead of going through the chunks and its entities in order to look for attackable players, the world's player list is checked.
The server needs to do alot more caching. Going through the chunks and doing a troublesome searches for the needed information everytime, costs a lot of the precious tick time.
I have also lowered the chance for a zombie to look for a new attackable target. 0 meant it always look for one, when this pathfindergoal was executed. 5 is a 20% chance, and 10 a 10% chance