Zone-entry permissions

Currently depends on https://github.com/ForgeEssentials/ForgeEssentialsMain/pull/1126 but can easily be changed to use old WarpPoint.

This PR implements permissions to deny players from entering zones by applying different effects (knockback, damage, potion, command).
The current permissions are 
````
fe.wb.command         # Execute this command if a player enters the area
fe.wb.damage          # Apply this amount of damage to players, if they are in this area
fe.wb.damage.timeout  # Time interval in milliseconds for applying damage-effect
fe.wb.knockback       # Deny players from entering this area by kicking them out of it
fe.wb.potion          # Apply potion effects to players who enter this area. Comma separated list of "ID:duration:amplifier" values. See http://www.minecraftwiki.net/wiki/Potion_effects#Parameters
fe.wb.potion.timeout  # Time interval in milliseconds for applying potion-effects
````

This is not intended for merging yet and more like a draft, but it already works.
Suggestions for improvement needed.