Bug Refixed B65-ZK-1889: zul.lang.wpd is always loaded twice with some
JS package merge configurations

http://tracker.zkoss.org/browse/ZK-1889
fine tune for security issue
Fix bug ZK-1896: ZK session timeout on JBoss AS 7 cluster issue
http://tracker.zkoss.org/browse/ZK-1896
B65-ZK-1900: Auto-complete Combobox in the bottom of the browser doesn't
sync dropdown position well http://tracker.zkoss.org/browse/ZK-1900
move sync popup position operations from ComboWidget.js to Combobox.js
minor fix sync combobox popup position