Add support to EntityExplodeEvent of Bukkit

This adds the support of Bukkits EntityExplodeEvent.
The implementation of this feature is a bit tricky, 
because you can't intercept an exploding Entity in Forge. 
There are simply no Forge-Events to do this. 
So you need to modify 2 Vanilla classes, to being able to call this event. 
The changes are reduced to the minimum and similar to the Bukkit-Implementation.
This allows for example WorldGuard to deny TNT explosions.