title: JsTree contextmenu callback functions not firing
body: <p>I am using the jstree library. A very nice library but I am stuck with one problem.  The callbacks of the contextmenu do not work.</p>
  
  <p>I made a small working example - it should give an alert when you add / remove / rename nodes, but nothing happens..</p>
  
  <p>Does anyone know why not and what is the solution?</p>
  
  <p>You can see the working- not working example online:
  <a href="http://www.leermetstrips.nl/Content/tree.htm" rel="nofollow">http://www.leermetstrips.nl/Content/tree.htm</a></p>
  
  <p>Or here:</p>
  
  <pre><code>&lt;!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"&gt;
  &lt;html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"&gt;
  &lt;head&gt;
      &lt;title&gt;JS tree example&lt;/title&gt;
      &lt;meta http-equiv="Content-Type" content="text/html; charset=UTF-8"&gt;
      &lt;script src="http://code.jquery.com/jquery-1.8.0.js"&gt;&lt;/script&gt;      
      &lt;script src="http://cachedcommons.org/cache/jquery-jstree/1.0.0/javascripts/jquery-jstree.js" type="text/javascript"&gt; &lt;/script&gt;    
  &lt;script type="text/javascript"&gt;
  $().ready( function() {
      var data = [{"data":"Root node","children":[{"data":"node one","children":[],"metadata":[{"action":"action12"}]}],"metadata":[{"action":"action11"}]}];
      $('#tree').jstree(
          {
              json_data: { data: data },
              plugins: ["themes", "json_data", "ui", "contextmenu", "crrm"],
              // TODO: this does not work, why?
              callback: {
                  oncreate: function (NODE, REF_NODE, TYPE, TREE_OBJ, RB) {
                      alert('oncreate');
                  },
                  onrename: function (NODE, LANG, TREE_OBJ, RB) {
                      alert('onrename');
                  },
                  ondelete: function (NODE, TREE_OBJ, RB) {
                      alert('ondelete');
                  }
              }
          }
          );
  });
  &lt;/script&gt;
  &lt;/head&gt;
  &lt;body&gt;
          &lt;h3&gt;JS tree example&lt;/h3&gt;
          &lt;p&gt;When adding, or deleting new nodes, there should be an alert. But there is none. Why?&lt;/p&gt;
          &lt;div id="tree" style="border:1px solid;"&gt;&lt;/div&gt; 
          &lt;p&gt;Click on the tree with your right mouse button to add, rename or delete NEW tree nodes.&lt;/p&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>