Fix collapsing tree node cause cellwidget missing
Fix column resize cursor disapper after mouse up
Fix header-body mismatch when focus on half hidden group header in IE
Fix clicking tree expando selects the cell
Fix subheader top border flashing issue
Fix selectRowTriggerOnCell not effective in IndirectSelectColumn
Remove unnecessary param declaration
Fix API doc of HeaderMenu and AZFilterMenu
Add group ID to GroupHeader API doc
Remove unused method and update API doc
Fix IE error when header region gets re-focus
Fire unrender before destroy nodes to avoid memleak
Fix Tree node expansion due to RowHeader error
Merge branch 'master' into 1.2