title: Knowing when a photo is deleted with Flickr API
body: <p>In my application, I have to run a periodical job where I need data about all the photos on my client's Flickr account. Currently, I perform several calls to flickr.photos.search to retrieve meta about all the photos each time.
  What I ask is: is there a way to be get informed by Flickr when a photo is modified or deleted, so that I don't need to retrieve metas for each photos, but rather store theme once, and only download what has changed since the last time I run the job ?
  Thx in advance for your help.</p>