fix null reference exception

null reference exception caused by loading default jail before the internal jail manager is finished initializing
move GlobalRegionManager to internal package

renamed GlobalRegionManager to InternalRegionManager and deleted the InternalRegionManager that extended GlobalRegionManager.

Add IGlobalRegionManager interface.

Add IRegionEventListener interface and add getEventListener method to IRegion to allow global region manager to call event handlers on a region.

refactored isPlayerWatcher method to isEventListener