title: TreeViewer: using Drag & Drop to reorder or reparent elements in a tree
body: <p>I have a TreeViewer of custom content. I'd like to be able to reorder it, much in the same was as the Outline View does currently when viewing Java Source.</p>
  
  <p>Is there any reference material or documentation out there on how to achieve this?</p>
  
  <p>Martin.</p>