Fix bug ZK-1594: Blinking popup in Firefox
http://tracker.zkoss.org/browse/ZK-1594
Fix bug ZK-1618: Tabpanel not follow the visible attribute
http://tracker.zkoss.org/browse/ZK-1618
Fix bug ZK-1622: Paging listbox scrollbar is wrong
http://tracker.zkoss.org/browse/ZK-1622
Bug ZK-1519: Popup disappear when mouse over on the corner where the two scrollbars meet, IE 10 only
remove log
Bug ZK-1868: TypeError: $tipOff is null in function _tt_close()
Merge branch '5.0' of github.com:zkoss/zk into 5.0
Bug fixed B50-ZK-1916: Different language codes for IE10 under Windows 8
http://tracker.zkoss.org/browse/ZK-1916