title: Internal inconsistency in a UITableView when the row count changes during a delete animation
body: <p><strong>The Scenario:</strong>
  I have a UITableView that displays data loaded from a network resource. A synchronization with that resource can take a while to complete, and the results are loaded in piecemeal. The network communication happens in the background via NSOperationQueue. Results are delivered via a notification, with control being transfered back to the main thread to insert the new results. The user is capable of performing operations on the data in the table while this is happening.</p>
  
  <p><strong>The Problem:</strong>
  If the user performs a delete operation on one of the rows in the table while the synchronization is happening, it is very likely that the row count will change while the table view is animating the deletion (because the animation results in several iterations through the event loop, and the notification handler for new results gets called). This leads to an internal inconsistency exception.</p>
  
  <p>The synchronization results in a call to reloadData on the table view as new results are loaded in batches. More importantly, it causes the row count to change.</p>
  
  <p>I have been unable to find a way to know that the table is animating (or be notified when it has finished), so that I can delay the processing of new results. Is this possible?</p>