ISPN-4643 Make sure EntryIterator doesn't return expired entries

https://issues.jboss.org/browse/ISPN-4643
That should be doable yes.  I admit I wasn't as worried about this since it was local only, but I should really change it.  Unfortunately it isn't as easy to do this change for DistributedEntryRetriever since it uses slightly different logic, but I can see if I can work it out there as well since it will probably be used much more frequently.