Leaves the current window group so that the window can be move independently of those in the group.
Example
var mainWindow = fin.desktop.Window.getCurrent(),
secondWindow = new fin.desktop.Window({
url: "http://www.openfin.co",
name: "secondWindow",
autoShow: true
}, function () {
// When mainWindow moves or is moved, secondWindow moves by the same amount
secondWindow.joinGroup(mainWindow, function() {
//once we are in the group, lets leave it.
secondWindow.leaveGroup();
});
});