title: Add custom menu item on wordpress 3.9.1 media upload
body: <p>I'm trying to add a menu item on Media Uploader of WordPress.</p>
  
  <p>It is like this screenshot: <img src="https://i.stack.imgur.com/9CNKc.png" alt="enter image description here"></p>
  
  <p>Basically, it should have the same functionality of <code>Create Gallery</code> with just different shortcode output.</p>
  
  <p>I've search Google for hours now and this has the closest thing of what I want: <a href="https://gist.github.com/Fab1en/4586865" rel="nofollow noreferrer">https://gist.github.com/Fab1en/4586865</a></p>
  
  <p>But it has an error which I can't figure out. (I have no knowledge on <code>Backbone.js</code>)</p>
  
  <pre><code>// create an input
  this.input = this.make( 'input', { // error line
      type:  'text',
      value: this.model.get('custom_data')
  });
  </code></pre>
  
  <p><code>Uncaught TypeError: undefined is not a function</code></p>
  
  <p>I think, if this will be fixed, everything will be good to go...</p>
  
  <p>Is there anyone who have tried this one? I need some help.</p>