Can viewControllerForUnwindSegueAction be removed once iOS 9 is in place

[whyceewhite]

In the MainViewController class a viewControllerForUnwindSegueAction is implemented because of a Swift bug where unwinding did not occur for tabbed controller views. According to this SO post, the unwinding should working in iOS 9. Once Swift and Xcode are updated in issue #18, check whether or not this superfluous override may be removed.

[whyceewhite]

The following block was removed as the segue works now in the upgraded swift/xcode versions.

/*
 * This override is needed to get the unwind segues to properly work.
 * See http://stackoverflow.com/questions/25654941/unwind-segue-not-working-in-ios-8
 */
override func viewControllerForUnwindSegueAction(action: Selector, fromViewController: UIViewController, withSender sender: AnyObject?) -> UIViewController? {

    return self.selectedViewController?.viewControllerForUnwindSegueAction(action, fromViewController: fromViewController, withSender: sender)
}

[whyceewhite]

Commit 96878d2