Updated changelog to include Wicket 6.6.0
WICKET-4998 + WICKET-4990 behaviors might be added via
IComponentInstantiationListeners, thus resulting in a
NullPointerException if AutoCompleteTextField adds its
AutoCompleteBehavior :( - now using trick with HeaderItem to make sure
the auto-complete event handler is able to register first
Merge branch 'master' of https://git-wip-us.apache.org/repos/asf/wicket
Update release script to actually upload the release artifacts to the staging area