title: Different ways of getting current interface orientation?
body: <p>There're 3 ways to get current interface orientation that I know of:</p>
  
  <ul>
  <li><code>self.interfaceOrientation</code></li>
  <li><code>[[UIApplication sharedApplication] statusBarOrientation]</code></li>
  <li><code>[[UIDevice currentDevice] orientation]</code></li>
  </ul>
  
  <p>What are the differences among them?</p>