HORNETQ-1146 use XMLUtils.* to ensure trimming.
Fixes https://community.jboss.org/message/799295
https://issues.jboss.org/browse/HORNETQ-1137 Optimization on queue-delivery, After this change we are not holding a lock on the queue while the consumer is delivering the packet to the client
Fixing groupIterator.remove as that would cause concurrentModificationException on the groupMaps