title: jstree validate renaming of node, and if not validated , roll back to old name
body: <p>while renaming a node in jstree, I wanted to validate for special characters in renaming, and if found , I wanted to alert user, and roll back to the old name.</p>
  
  <p>for that I have added </p>
  
  <ul>
  <li>rename context menu</li>
  <li>after that I did bind with node_rename and rename event</li>
  <li>in binding I check for event.type === node_rename</li>
  <li>I am able to validate special characters of new name as I get new name in data.args[1]</li>
  <li>but before my alert comes, rename is already taken place, and I dont find a way to undo that.</li>
  </ul>
  
  <p>Any help is appreciated.</p>