title: Startup-Log "No Transaction manager found"
body: <p>When I start jetty, following line appears in Log:</p>
  
  <pre><code>:INFO:oejpw.PlusConfiguration:No Transaction manager found
  - if your webapp requires one, please configure one.
  </code></pre>
  
  <ul>
  <li>What does it means?</li>
  <li>How do I know that my webapp requires a transaction manager?</li>
  <li>Which features serves such transaction manager or what am I missing if I do not have one?</li>
  </ul>