title: How to convert a project using XIBs to Storyboard?
body: <p>I have some complex XIB files in a project using TabBarViewControllers containing navigation controllers. Since Xcode 4.2 I cannot edit those XIB files usefully anymore: the contained view controllers are invisible, only represented as grey boxes. It seems that in Storyboard projects this is the default, and the next layer in the storyboard shows the details of the contained views / view controllers. So how can I switch my project to use a storyboard instead?</p>