title: How to use the CVS commitid feature?
body: <p>I've noticed that newer versions of CVS use commitids.</p>
  
  <p>I guess this is a recent addition - because 'back in the days' there was no such thing.</p>
  
  <p>Googling around I find mostly comments related to CVSNT - but it seems that commitids are also present in standard open source CVS.</p>
  
  <p>How can I take advantage of the commitid feature (in standard CVS)?</p>
  
  <p>For example:</p>
  
  <ul>
  <li>How to display a diff between to commitids?</li>
  <li>How to list the files/version-numbers that are associated to a certain commitid?</li>
  </ul>