title: Wallpaper change event
body: <p>Can I get a wallpaper changed event in a broadcast receiver?
  I need to detect if the user changed the wall paper.
  How could I do it?</p>
  
  <p>What I am doing is this:
  I have an app that changes wallpaper automaticly.
  If the user changes it manually using a different aplication I would like to notice it and ask the users if he/she wants to add that new wallpaper to the list in my application</p>