Bug 249574 [Contributions] ExternalActionManager.addPropertyChangeListener() doesn't register the ListenerList
bundles/org.eclipse.jface/src/org/eclipse/jface/action/ExternalActionManager.java
final Trigger[] triggers = triggerSequence.getTriggers();
				if (triggers.length == 1) {
					final Trigger trigger = triggers[0];
					if (trigger instanceof KeyStroke) {
						final KeyStroke keyStroke = (KeyStroke) trigger;
						final int accelerator = SWTKeySupport
								.convertKeyStrokeToAccelerator(keyStroke);
						return new Integer(accelerator);
					}
				}
			}
			return null;
		}
		/**
		 * @see org.eclipse.jface.action.ExternalActionManager.ICallback#getAcceleratorText(String)
		 */
		public final String getAcceleratorText(final String commandId) {
			final TriggerSequence triggerSequence = bindingManager
					.getBestActiveBindingFor(commandId);
			if (triggerSequence == null) {
				return null;
			}
			return triggerSequence.format();
		}
		/**
		 * Returns the active bindings for a particular command identifier.
		 * 
		 * @param commandId
		 *            The identifier of the command whose bindings are
		 *            requested. This argument may be <code>null</code>. It