Support pasting with right mouse click and "paste" group name from the context menu
into the input field and enable the "Create Group" button.
For 'Event.ONPASTE' Gwt(2.5.0) Note: "This event is not supported on Firefox 2 and
earlier, or Opera 10 and earlier. Be aware that it will not fire on these browser
versions."
Bug: Issue 1843
Change-Id: I5a866fd84def719b70d0f55c89188efdce4cf2ff
cb0a36e6d3