title: Hide a UIBarButtonItem when in edit mode
body: <p>I have a <code>UINavigationController</code> with a <code>UITableViewController</code> which has and two <code>UIBarButtonItem</code>s:</p>
  
  <pre><code>- (void)viewDidLoad {
      [super viewDidLoad];
  
  
      self.navigationItem.leftBarButtonItem = self.editButtonItem;
      self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(showSubscribeSheet:)];
  
      self.navigationController.navigationBar.tintColor = [UIColor brownColor];
  }
  </code></pre>
  
  <p>I want to hide <code>self.navigationItem.rightBarButtonItem</code> when the <code>UITableView</code> is in edit mode. What way can I do this? Thanks.</p>
  
  <hr>
  
  <p>I do not use nibs.</p>