title: How to reordering rows in NSTableView with NSArrayController
body: <p>i've got <code>NSArrayController</code> which gives my <code>NSTableView</code> object data from array <code>_files</code>.
  The problem is i want to reorder rows by dragging. How can i do this correclty with <code>NSArrayController</code>?</p>
  
  <p>Thank you for help.</p>