title: UITabBarController "want full screen" setting
body: <p>In IB for an UITabBarController, there is a setting for each view controller for each tab that called "want full screen".  The book I am reading says that if you want to display your view in full screen then select that option.  But you will need to have away to get back to your tab bar.  Unfortunately, this book does not have any samples that use this setting.  And I have tried myself but when I tapped on the tap bar the resulted view is not full screen.  Any one know how to use it properly?</p>