title: Show only checked nodes and parents of it in jstree
body: <p>I have to show only selected nodes and parents, and hide rest nodes.</p>
  
  <p>There is no get_unchecked in current documentation. My json format is huge so taking it in string and formatting and reloading tree will be inefficient.</p>
  
  <p>Is there a way to get all unchecked nodes and hide it?
  if there is i can check all parent node of current checked node and then just hide all unchecked nodes, but i cannot find any method to retrive all unchecked nodes. </p>