title: UITabBarController/UINavigationController missing title
body: <p>I have a UINavigationController and UITabBarController visible at the same time.  Both the tab bar buttons and the navigation bar take their text from the title of the currently active view.</p>
  
  <pre><code>- (void)viewDidLoad {
      [super viewDidLoad];
      self.title = @"View Title";
  </code></pre>
  
  <p>However I want the different.  In fact I'd like the navigation controller title to remain the same whichever view is being displayed.</p>
  
  <p>Any ideas?</p>
  
  <p>Many thanks.</p>