Bug 249574 [Contributions] ExternalActionManager.addPropertyChangeListener() doesn't register the ListenerList
bundles/org.eclipse.jface/src/org/eclipse/jface/action/ExternalActionManager.java
/**
		 * Fires a <code>NotEnabledException</code> because the action was not
		 * enabled.
		 * 
		 * @param action
		 * 			The action contribution that caused the exception,
		 * 			never <code>null</code>.
		 * @param exception
		 * 			The <code>NotEnabledException</code>, never <code>null</code>.
		 */
		public void notEnabled(IAction action, NotEnabledException exception);
		/**
		 * Fires a <code>NotDefinedException</code> because the action was not
		 * defined.
		 * 
		 * @param action
		 * 			The action contribution that caused the exception,
		 * 			never <code>null</code>.
		 * @param exception
		 * 			The <code>NotDefinedException</code>, never <code>null</code>.
		 */
		public void notDefined(IAction action, NotDefinedException exception);
		
		/**