title: Python PyQt Pyside - setNameFilters in QFileDialog does not work
body: <p>(Windows 7 64 Bit, PyCharm 3.4.1 Pro, Python 3.4.0, PySide 1.2.2)</p>
  
  <p>I want to make a file dialog with filters and preselect one filter.</p>
  
  <p>If i use the static method, it works, i can use filters and preselect one filter.</p>
  
  <pre><code>dir = self.sourceDir
  filters = "Text files (*.txt);;Images (*.png *.xpm *.jpg)"
  selected_filter = "Images (*.png *.xpm *.jpg)"
  fileObj = QFileDialog.getOpenFileName(self, " File dialog ", dir, filters, selected_filter)
  </code></pre>
  
  <p>If i use an object it does not work, my filters are not there.</p>
  
  <pre><code>file_dialog = QFileDialog(self)
  file_dialog.setNameFilters("Text files (*.txt);;Images (*.png *.jpg)")
  file_dialog.selectNameFilter("Images (*.png *.jpg)")
  file_dialog.getOpenFileName() 
  </code></pre>
  
  <p>Why does this not work?</p>
  
  <p><img src="https://i.stack.imgur.com/GK5tL.jpg" alt="enter image description here">
  <img src="https://i.stack.imgur.com/JOo0C.jpg" alt="enter image description here"></p>