title: iOS7 hide status bar but not adjust top layout guide
body: <p>I deal with autolayout set up in Interface Builder. I want to not offset views that are pinned to top layout guide when I hide status bar in runtime.</p>
  
  <p>I have discovered that <code>myViewController.topLayoutGuide.length</code> changes from 20 to 0 when hiding status bar. How to prevent it? Or (as workaround) how to set up fullscreen view for various window sizes without pin to top layout guide?</p>
  
  <p>Some code to describe my situation:</p>
  
  <pre><code>Log(@"frame: %@, top: %.0f", NSStringFromCGRect(myViewController.myView.frame), self.topLayoutGuide.length);
  [[UIApplication sharedApplication] setStatusBarHidden:YES withAnimation:UIStatusBarAnimationNone];
  Log(@"frame: %@, top: %.0f", NSStringFromCGRect(myViewController.myView.frame), self.topLayoutGuide.length);
  </code></pre>
  
  <p>Output:</p>
  
  <pre><code>frame: {{40, 24}, {240, 40}}, top: 20
  frame: {{40, 4}, {240, 40}}, top: 0
  </code></pre>