title: NSBatchDeleteRequest does not delete relationship
body: <p>I have a problem with <code>NSBatchDeleteRequest</code> seems that is not possible to delete relationship references.</p>
  <p>I have two entities:</p>
  <ul>
  <li>News</li>
  <li>Categories</li>
  </ul>
  <p>where a category can have multiple news.</p>
  <p>Now, when I try to delete all the objects in the core data using <code>NSBatchDeleteRequest</code> with the following code, then looking into the sqlite file seems that all categories are deleted, all news are deleted, but the relationship between categories and news persists, and this cause faults.</p>
  <p>Here the delete function:</p>
  <pre><code>NSFetchRequest *fetchRequest = [NSFetchRequest fetchRequestWithEntityName:entityName];
  NSBatchDeleteRequest *delete = [[NSBatchDeleteRequest alloc] initWithFetchRequest:fetchRequest];
  [delete setResultType:NSBatchDeleteResultTypeCount];
  NSError *error;
  NSBatchDeleteResult *results = [deleteContext executeRequest:delete error:&amp;error];
  </code></pre>
  <p>Any idea on how to fix this?</p>