title: jsTree "create_node" really not working
body: <p>I am trying to dynamically add a new node in my jsTree container. It is not working at all. I don't know what i am missing.</p>
  
  <p><a href="http://jsfiddle.net/FWgQa/1/" rel="noreferrer">jsfiddle example</a></p>
  
  <pre><code>$("#tree").jstree({
      core: {
          "animation": 0
      },
      "html_data": {},
      "themes": {
          "icons": false
      },
      "search": {
          "case_insensitive": true,
          "show_only_matches": true
      },
      "plugins": ["themes", "html_data", "search"]
  });
  
  $("#tree").jstree("create_node", $("node_1"), "after", { "data": "Hello World" });
  </code></pre>
  
  <p>html:</p>
  
  <pre><code>&lt;div id="tree"&gt;
      &lt;ul&gt;
          &lt;li id="node1"&gt;&lt;a&gt;Hello&lt;/a&gt;&lt;/li&gt;
      &lt;/ul&gt;
  &lt;/div&gt;
  </code></pre>