Support UIViewController Lifecycle

[barylevy]

When you slide between view controllers, the view controller does not get the following callbacks while it appear/disapear:

override public func viewDidAppear( animated: Bool) {} override func viewWillAppear( animated: Bool) {} override func viewDidDisappear( animated: Bool) {} override public func viewWillDisappear( animated: Bool) {} override func viewDidDisappear(_ animated: Bool) {}

I want to add it