title: UINavigationController Interactive Pop Gesture Not Working?
body: <p>So I have a navigation controller in my built for iOS 7 app.  The titleView is visible, as well as the back button and navigation bar its self.  For some reason, the interactive pop gesture (swipe from the left edge) isn't working.  Nothing happens.  When I log the gesture, it is not nil.  Is there anything special I have to do to enable this functionality?  What could cause it not to work?</p>