title: In PHPhotoLibrary, photoLibraryDidChange doesn't notify all update
body: <p>I'm using <code>PHPhotoLibrary</code> to save and fetch images for my application's album in iPhone.</p>
  
  <p>When my album has a lot of images (about 5,000 still images),
  my application download 10 images from network, then save to Camera roll and add to my application's album.</p>
  
  <p>At the same time, the application observe <code>photoLibraryDidChange</code> callback to know the added images, but it notify only 5 inserted images.</p>
  
  <p>I finish my application by pushing HOME button and check Camera roll and my album in Photo App. <strong>There are correctly 5010 images.</strong></p>
  
  <p>Maybe <code>photoLibraryDidChagne</code> doesn't notify all changes ?</p>
  
  <p>My code is like below.</p>
  
  <pre><code>- (void)photoLibraryDidChange:(PHChange *)changeInstance
  {
      // dispatch main queue
      dispatch_async(dispatch_get_main_queue(), ^{
          [self handleChangedLibrary:changeInstance];
      });
  }
  
  - (void)handleChangedLibrary:(PHChange *)changeInstance
  {
      PHFetchResultChangeDetails *fetchResultChangeDetails = [changeInstance changeDetailsForFetchResult:_assetsFetchResult];
  
      if (!fetchResultChangeDetails) {
          NSLog(@"### No change in fetchResultChangeDetails ###");
          return;
      }
  
      if (![fetchResultChangeDetails hasIncrementalChanges]) {
          [self fetchAllAssets];
          return;
      }
  
      NSArray *insertedObjects = [fetchResultChangeDetails insertedObjects];
      if (insertedObjects) {
          for (PHAsset *asset in insertedObjects) {
              if (asset.mediaType == PHAssetMediaTypeImage) {
                  NSLog(@"asset=%@", asset);
                  [_stillImageAssetArray addObject:asset];
              }
          }
      }
  
      self.assetsFetchResult = [PHAsset fetchAssetsInAssetCollection:_assetCollection options:nil];
  }
  </code></pre>
  
  <p>I checked inserted asset by NSLog and Debugger and it truly updated 5 images.</p>
  
  <p>There is no notification for the other 5 images.</p>