title: PyQt4: Sorting a QTableWidget by a column containing an icon
body: <p>I have a database with a list of items, and each item has an associated "rating" field, which is a float ranging from 0-5. Now, when I'm populating the QTableWidget with these items, I want to display an image for the rating instead of the float. So I do this:</p>
  
  <pre><code>iconPath = "images/icons/ratings/"+backend.utilities.pickRatingIcon(col)
  icon = QtGui.QIcon(QtGui.QPixmap(iconPath))
  item = QtGui.QTableWidgetItem(icon, "")
  self.deckTable.setItem(i, j, item)
  </code></pre>
  
  <p>Everything works, but I naturally lose my ability to sort by that column. I can change the third line to this:</p>
  
  <pre><code>item = QtGui.QTableWidgetItem(icon, col)
  </code></pre>
  
  <p>which allows me to sort again, but then I get the float next to the icon which kind of defeats the purpose. Is there a way to display just the icon but sort by the value?</p>