Started exploring how filters could be handled
Working on filters, and sorting. Commit temporary, must interrupt work for a couple of hours
GenericNotificationProducer should be about finished. Filters are not implemented, but the framework around them is
SimpleNotificationProducer now removes outdated subscriptions.This is done when it sends out a Notify
GenericNotificationProducer now removes its subscriptions on notify send
Updated GenericNotificationProducer and filter handling to better fit the spec
Added shallow clone of Notify to ServiceUtilities
Set up for NameSpaceContext fetch and evaluation in filters
Topic filter should now be valid

This caused additions to topic package in main, especially the
"isLegalExpression" in TopicValidator and the same named method in
TopicExpressionEvaluatorInterface. NamespaceContext had to be introduced
when evaluating filters; needed to correctly evaluate XPath (and similar).
DefaultMessageContentFilterEcaluator finished

Not tested, but that is on its way.
Added some helper methods in ServiceUtilities for QueryExpressions and
exceptions/faults.
Removed unused imports
Added XML for filter tests
Fixed bug in SimpleEvaluator, determined need for better checking of the other three topic evaluators; Tests that assumes these to be correct fails
XML updated for topic testing. Linked and loaded in test
Updated dialects in test XML
Testwriting for Topics