title: MPMusicPlayerController and setNowPlayingItem
body: <p>I'm using <code>MPMusicPlayerController</code>, specifically with <code>setNowPlayingItem</code> protocol and it's for <code>cydia</code>. But I have some issues and theos' warning when i make. It seems that some of the protocols and methods are not working and I receive some warning like this:</p>
  
  <pre><code>Tweak.xm:177: warning: ‘MPMusicPlayerController’ may not respond to ‘-skipToPreviousItem’
  Tweak.xm:188: warning: ‘MPMusicPlayerController’ may not respond to ‘-pause’
  Tweak.xm:193: warning: ‘MPMusicPlayerController’ may not respond to ‘-play’
  Tweak.xm:201: warning: ‘MPMusicPlayerController’ may not respond to ‘-skipToNextItem’
  Tweak.xm:317: warning: ‘MPMusicPlayerController’ may not respond to ‘-setNowPlayingItem:’
  </code></pre>
  
  <p>Have anyone some ideas? I enter the protocol already in prototype</p>