title: Comparing two ObservableCollection(s) to see if they are different
body: <p>I'm working on comparing two versions of a listview, for a settings form. I need to know if the user actually modified the list at all, in which case when they click "Save" I'll actually save. If they didn't change anything, when they click "Save" I won't be wasting memory/time re-saving something they didn't change.</p>
  
  <p><strong>Anyway, how can I compare two ObservableCollections to see if they are at all different?</strong></p>
  
  <p>Thanks in advance!</p>