title: QProgressDialog doesn't paint during initializeGL
body: <p>I'm using a <code>QProgressDialog</code> to display the progress of my <code>initializeGL()</code> function but the little window show up unpainted... Here's the simplified code :</p>
  
  <pre><code>QProgressDialog barTest("Wait","Ok", 0, 100, this);
  
  barTest.move(400,400);
  
  barTest.show();
  
  for(int i = 0; i &lt; 100; i++)
  {
      barTest.setValue(i);
      qDebug() &lt;&lt; i;
  }
  </code></pre>
  
  <p>I'm running <code>Mac OS 10.8</code></p>