title: How to make QFileDialog not modal in Qt5?
body: <p>In previous versions of Qt we were able to use following constructor of file dialog:</p>
  
  <pre><code>QFileDialog(QWidget * parent = 0, const char * name = 0, bool modal = FALSE)
  </code></pre>
  
  <p>So, it looks like it was possible to make non-modal file dialog. But now (in Qt5) we haven't such parameters in constructor. Also QFileDialog ignores <code>setWindowModality(Qt::NonModal);</code> and <code>setModal(false);</code> (I've checked, that if <code>windowModality() == Qt::NonModal &amp;&amp; isModal() == false</code>, file dialog window is still modal).</p>
  
  <p><strong>Do you have ideas, how to make my file dialog non-modal?</strong></p>
  
  <p>Details: my file dialog inherited from QFileDialog. It works absolutely as expected. The only thing I need is to make it non-modal, but I can't find solution on SO and on qt-project. Thank you in advance.</p>