refix zk-1908
fine tune fix of Bug ZK-1885
refix icon missing when collapse
add a tag into tab if tab doesnt have caption
bug fixed: font chagne when hover in ie8
rm ie6 css, bug fixed: the popup of gmap should not have scrollbar
Bug ZK-1906: Chosenbox getSelectedObjects() returns empty list if model is ListModel of JavaBean instances instead of ListModel of String
fine tune: tab.js
fine tune: tab.js
Merge branch 'fix-ie8' of https://github.com/huangnoah/zk into fix-ie8

Conflicts:
	zul/src/archive/web/js/zul/tab/mold/tab.js
fine tune fix of Bug ZK-1885
reset HeadWidget.js
style fixed: the slider should show well when click at rail in ie8
B50-3188023: the Listbox add timeout fn into onSize() like grid, tree
style fixed: the h/vbox should show well in ie8
minor fix
fix ie8 scrollbar issue
Bug fixed B50-ZK-1916: Different language codes for IE10 under Windows 8
http://tracker.zkoss.org/browse/ZK-1916
bug fixed: the icon inside groupbox should show well when groupbox open
borderlayout style minor fix