title: Getting NSMenuItem of NSMenu tree by title
body: <p>I have an <code>NSMenu</code> (let's say the Main Menu), with lots of <code>NSMenu</code>s in it, and <code>NSMenuItem</code>s at different levels.</p>
  
  <p>I want to be able to get the NSMenuItem instance specifying the tree path (with the title of the corresponding NSMenus/NSMenuItems in it).</p>
  
  <p><strong>Example :</strong></p>
  
  <blockquote>
    <p>Menu :</p>
    
    <ul>
    <li>File
    <ul>
    <li>New</li>
    <li>Open
    <ul>
    <li>Document</li>
    <li>Project</li>
    </ul></li>
    <li>Save</li>
    <li>Save As...</li>
    </ul></li>
    </ul>
    
    <p><strong>Path :</strong> /File/Open/Document</p>
  </blockquote>
  
  <p>How would you go about it, in the most efficient and Cocoa-friendly way?</p>