Guarantee order of listener notifications

Author: papegaaij

wicket-util/src/main/java/org/apache/wicket/util/listener/ListenerCollection.java

@@ -28,7 +28,8 @@
 /**
  * Represents a collection of listeners. Facilitates invocation of events on each listener.
  * <p>
- * NOTE: Ordering of listeners is not guaranteed and should not be relied upon
+ * Listeners will be invoked in the order added to the collection when using
+ * {@link #notify(INotifier)} or in reversed order when using {@link #reversedNotify(INotifier)}.
  * </p>
  * 
  * @author ivaynberg (Igor Vaynberg)