title: Qt QDateTime from string with timezone and daylight saving
body: <p>i am inserting time from string</p>
  
  <pre><code>QDateTime time =QDateTime::fromString("Wed Mar 26 22:37:40 2019 GMT-08");
  qDebug()&lt;&lt;time.toLocalTime().toString();
  qDebug()&lt;&lt;time.toUTC().toString();
  qDebug()&lt;&lt;time.isDaylightTime();
  </code></pre>
  
  <p>output i am getting as</p>
  
  <ul>
  <li>"Tue Mar 26 23:37:40 2019" </li>
  <li>"Wed Mar 27 06:37:40 2019 GMT" </li>
  <li>false</li>
  </ul>
  
  <p>it should have given</p>
  
  <ul>
  <li>"Tue Mar 26 23:37:40 2019" </li>
  <li>"Wed Mar 27 05:37:40 2019 GMT" </li>
  <li>true</li>
  </ul>
  
  <p>how can i pass daylight saving with the timestamp string?</p>