title: How to get the index of selected nodes in jstree
body: <p>I want to use jstree to let the user select nodes and reorder the tree using the drag'n'drop plugin. 
  Here's a jsfiddle demonstrating the current behaviour: </p>
  
  <pre><code>$("#ProductInterests").jstree({
      core: { themes: { icons: false },"check_callback" : true },
      checkbox : { tie_selection : false },
      plugins: ["themes", "checkbox","dnd"]
  });
  
  $('button').click(function () {
      alert($("#ProductInterests").jstree(true).get_checked().join(','));
  });
  </code></pre>
  
  <p><a href="http://jsfiddle.net/dt2rk2d1/" rel="nofollow">http://jsfiddle.net/dt2rk2d1/</a></p>
  
  <p>At the moment, all selected ids are reported in the order they where selected. Is it possible to get them in the order they appear in the tree? Even after the user drag'n'dropped the items?</p>