title: how to make getOpenFileName remember last opening path?
body: <p>According to getOpenFileName instructions:</p>
  
  <pre><code>QString fileName = QFileDialog.getOpenFileName(this, tr("Open File"), 
                                            "/home",
                                            tr("Images (*.png *.xpm *.jpg)"));
  </code></pre>
  
  <p>How can I make the dialog remember the path the last time when I close it?</p>
  
  <p>and what does the tr mean in the <code>tr("Open File")</code>? </p>
  
  <p>Thanks</p>