title: Observable Collection Property Changed on Item in the Collection
body: <p>I have an <code>ObservableCollection&lt;T&gt;</code>. I've bound it to a ListBox control and I've added <code>SortDescriptions</code> to the Items collection on the ListBox to make the list sort how I want. </p>
  
  <p>I want to resort the list at <strong>ANY</strong> point when any property changed on a child element.  </p>
  
  <p>All my child elements implement <code>INotifyPropertyChanged</code>.</p>