title: Show UIAlertController from a common utility class
body: <p>I am working on a project that uses <code>UIAlertView</code>, now the problem is I have to replace all of the <code>UIAlertView's</code> with <code>UIAlertController's</code> and there are around 1250 of them in the code. I am planning to uses the existing Utility class to create a function that does this, following is what I am planning to do:</p>
  
  <pre><code>+(void)showAlert:(NSString *)title errorMessage:(NSString *)msg {
      UIAlertController *alertController = [UIAlertController 
      alertControllerWithTitle:title message:msg preferredStyle:UIAlertControllerStyleAlert];
      [alertController addAction:[UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:nil]];
      [self presentViewController:alertController animated:YES completion:nil];
  }
  </code></pre>
  
  <p>I have the following questions before doing this:
  1 - Is this worth the efforts (Using <code>UIAlertController</code> instead of <code>UIAlertView</code>) ?
  2 - How do I handle <code>UIAlertView's</code> that had tags and different delegate implementation across hundreds of files ?
  3 - The fourth line the function above gives an error : <code>No known class method for selector 'presentViewController:animated:completion:'</code></p>
  
  <p>Any help is greatly appreciated.</p>