title: setFont for UIButton is deprecated, I tried new method but keep failed
body: <p>I want to customise all my buttons with my own font using this code :</p>
  
  <pre><code>// Custom fonts for button with tag
  for (UIButton *customButton in [[self view] subviews]) {
      if (customButton.tag == 1) {
          customButton.titleLabel.font = [UIFont fontWithName:@"OpenSans-Regular" size:14];
      }
  }
  </code></pre>
  
  <p>but I got this error message on my debugger console :</p>
  
  <pre><code>2013-09-21 00:33:33.160 Test[794:907] -[UILabel titleLabel]: unrecognized selector sent to instance 0x1dda8d80
  2013-09-21 00:33:33.165 Test[794:907] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[UILabel titleLabel]: unrecognized selector sent to instance 0x1dda8d80'
  </code></pre>
  
  <p>what did I do wrong? I'm using XCode 4.6.3 and targeting iOS6. thank you...</p>