title: Make the CodeMirror merge view addon display a count of differences found
body: <p>While using CodeMirror’s <a href="http://codemirror.net/demo/merge.html" rel="nofollow"><code>merge</code> addon</a>, I am interested in knowing the <em>count of differences</em> found in the L.H.S. and the R.H.S. <code>textarea</code>s, respectively.</p>
  
  <p>Is there a way of displaying the count?</p>