Bug fixed ZK-2028: When deleted one selected item in chosenbox with
ListSubModel, it would remove all the selection
http://tracker.zkoss.org/browse/ZK-2028
Bug fixed B65-ZK-2019: Chosenbox work incorrectly when using
ListSubModel and Comparator
http://tracker.zkoss.org/browse/ZK-2019
Merge remote-tracking branch 'Raymond/B65-ZK-2019' into 6.5