title: NSFetchedResultsController with multiple section logic
body: <p>I have a list of items that are added to a shopping list.  Each item has a department, and a flag to say whether it has been collected or not.</p>
  
  <p>I would love to use a single table view to display this.  The problem is, I need to group the sections by department, and then add a final additional section at the bottom for collected items (regardless of departments).</p>
  
  <p>I can create a fetchedResultsController filtering out collected = yes and sorting by department easily enough.  But I need this additional section appended with those items where collected = yes.</p>
  
  <p>Should I be trying to create a fetchedResultsController with a sophisticated query to do this?  Or try to manually add a section and some rows?  If so, from where?  A second FRC? Is it possible to have two FRCs feed into a single tableview?</p>