title: add a back button to UIImagepicker controller navigation nar
body: <p>i have a UI Image picker and its being shown inside a UI popoverController, i need a back button on UIimage picker navbar, so i can go back to previous popover.</p>
  
  <p>let me explain in details. 
  1) i have a popup in which i tap and raise a notification, this notification is read on a view controller where i want this camera image picker popup. following is my code</p>
  
  <pre><code>-(void)registerNotificationForCameraSource
  {
   [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(mediaSourceCallback:) name:NOTIFICATION_FOR_CAMERA_SOURCE object:nil];
  }
  
   #pragma mark - Image picker Popover
  -(void)mediaSourceCallback:(NSNotification *)notificationObj
     {
   capturedImages = [[NSMutableArray alloc] init];
   pickerObj = [[UIImagePickerController alloc] init];
  // [pickerObj setContentSizeForViewInPopover:CGSizeMake(320,480)];
  pickerObj.delegate = self;
  
  if ([notificationObj.object isEqualToString:@"UIImagePickerControllerSourceTypeCamera"])
  {
      pickerObj.sourceType = UIImagePickerControllerSourceTypeCamera;
      pickerObj.modalPresentationStyle = UIModalPresentationFullScreen;
      pickerObj.showsCameraControls = YES;
       [self presentViewController:pickerObj animated:YES completion:nil];
  
  }
  else
  {
  
      [[UINavigationBar appearanceWhenContainedIn:[ApplicationDiscriptionPopupViewController class], nil] setBarTintColor:[UIColor redColor]];
  
    pickerObj.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc]initWithTitle:@"Back" style:UIBarButtonItemStyleDone target:self action:@selector(imagePickerBackButtonTapped)];
  
      [pickerObj.navigationController.navigationBar setBarTintColor:[UIColor redColor]];
  
      [pickerObj setNavigationBarHidden:NO animated:YES];
  
      //navigationControllerObj = [[UINavigationController alloc] initWithRootViewController:applicationDiscriptionPopupViewControllerObj];
  
  
      _popoverControllerObj.popoverContentSize = CGSizeMake(320,480);
      pickerObj.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
      [pickerObj presentedViewController];
      [_popoverControllerObj setContentViewController:pickerObj animated:YES];
  }
  
  }
   -(void)imagePickerBackButtonTapped
   {
   [pickerObj popToViewController:applicationDiscriptionPopupViewControllerObj    animated:YES]; }
  </code></pre>
  
  <p><em>pickerObj</em> is UI Image picker</p>
  
  <p><em>applicationDiscriptionPopupViewControllerObj</em> is view controller of my previous popover view. from where i came. now i wana go back to this view in the popup, when i tap on back button in nav bar.</p>
  
  <p>but i dnt hav any nav bar. plz help</p>