title: format date/time value shown by a QTableView
body: <p>I´m using a <a href="http://doc.qt.io/qt-5/qtableview.html" rel="nofollow noreferrer">QTableView</a> to show a database table via model. One of the table columns have a timestamp, acctually a QDateTime was stored there before.</p>
  
  <p>Is there some way to format the timestamp value at presentation time? I was thinking in something like the .toString of a <code>QDateTime("yyyy-MM-dd hh:mm:ss.zzz")</code>.</p>