title: PyQt4 QSpinBox value format
body: <p>My objective is to use a <code>QSpinBox</code> to display the numbers from <strong>0 to 9999 with the increasement of 1</strong> using 4-digits format.</p>
  
  <p>I managed to set the Maximum value 9999 by using <code>setMaximum</code> command. But I can't seems to find a way to display the values in 4digits format (eg. 0000, 0001,0002). Whenever i set the value to <strong>0000</strong>  using <code>setValue</code> , the SpinBox display as <strong>0</strong>. </p>
  
  <p>How do i display the numbers in 4-digits format (i.e adding leading zero as required) in <code>QSpinBox</code>?</p>