title: Setting QDockWidget::title StyleSheet
body: <p>My initial problem was to make QDockWidget title bold.
  I tried this and it worked:</p>
  
  <pre><code>myDock-&gt;setStyleSheet("QDockWidget { font: bold }");
  </code></pre>
  
  <p>But I can't understand why the following code doesn't work:</p>
  
  <pre><code>myDock-&gt;setStyleSheet("QDockWidget::title { font: bold }";
  </code></pre>
  
  <p>Even if I use more complicated style sheet, every parameter of it has effect except for <code>font: bold</code>:</p>
  
  <pre><code>myDock-&gt;setStyleSheet("QDockWidget::title { font: bold;
                                              text-align: left; 
                                              background: red; 
                                              padding-left: 30px; }");
  </code></pre>
  
  <p>What is the problem with QDockWidget::title font?</p>