title: get file name when using writeImageToSavedPhotosAlbum
body: <p>in an ios swift application,
  I am using <code>writeImageToSavedPhotosAlbum</code> to save a UIImage on the iphone</p>
  
  <pre><code>let assets : ALAssetsLibrary = ALAssetsLibrary()
  let imgRef : CGImage = myImage!.CGImage
  let orientation : ALAssetOrientation = ALAssetOrientation(rawValue: myImage!.imageOrientation.rawValue)!
  assets.writeImageToSavedPhotosAlbum(imgRef, orientation: orientation, completionBlock: nil)
  </code></pre>
  
  <p>Is there a way I can get the saved image filename? or maybe to set it myself?</p>
  
  <p>Thank you for any help</p>