fix mvvm performance issue
Fix bug ZK-1480
http://tracker.zkoss.org/browse/ZK-1480
Fix bug ZK-1512: ListBox Select All
http://tracker.zkoss.org/browse/ZK-1512
add test case
release 6.0.4
update version to 6.0.5
Fix bug ZK-1531: Button with an image attribute will fire both click and rightClick events when right click the mouse in Chrome
http://tracker.zkoss.org/browse/ZK-1531
Fix bug ZK-1523
http://tracker.zkoss.org/browse/ZK-1523
Fix javadoc's typo.
Fix bug ZK-1381 on Chrome/Safari
Modify release note
Fix bug ZK-1578: window hflex="min" not work
http://tracker.zkoss.org/browse/ZK-1578
Fix bug ZK-1572: Scrolling-Bug in Listbox with freezed columns with ie9
http://tracker.zkoss.org/browse/ZK-1572
Fix bug ZK-1579: hflex="1" not work after changing visible state
http://tracker.zkoss.org/browse/ZK-1579
Merge remote-tracking branch 'VincentJian/B65-ZK-1578'
Fix bug ZK-1577: vlayout default spacing missing when groupbox has hflex="1"
http://tracker.zkoss.org/browse/ZK-1577
Fix bug ZK-1535: Bug in ZK 6.5.1 :: Calendar component does not display the 6th week
http://tracker.zkoss.org/browse/ZK-1535
Feature ZK-1583: notification arrow position shall align in the center of reference widget
http://tracker.zkoss.org/browse/ZK-1583
Fix bug ZK-1587: Textbox value is wrong when popup close, IE only
http://tracker.zkoss.org/browse/ZK-1587
Merge remote-tracking branch 'VincentJian/B65-ZK-1577'