Bukkit

DELETE YOUR OLD CONFIGURATION FILE

- added check if mob-spawning is prevented by worldguard on the mounting location,
      fix: if mob-spawning is not allowed, you will not mount an unvisible dragon anymore.
- updated event listeners to the new bukkit event system
- added configurable withdraw-message "WithdrawMessage"
- added command /dt remdragons, which removes all enderdragons on the same world
  as the executor of this command, which do not have players as passengers