title: Symfony sfWidgetFormChoice default disabled value
body: <p>The widget looks like this:</p>
  
  <pre><code>$this-&gt;widgetSchema['tara'] = new sfWidgetFormChoice(array(
      'choices'  =&gt; Doctrine_Core::getTable('Users')-&gt;getCountry(),
      'expanded' =&gt; false,
      'multiple' =&gt; false,
  ));
  </code></pre>
  
  <p>And the <strong>getCountry</strong> function:</p>
  
  <pre><code>static public $country = array(
      '1' =&gt; 'România',
      '2' =&gt; 'United States',
      '3' =&gt; 'France',
  );
  
  public function getCountry()
  {
      return self::$country;
  }
  </code></pre>
  
  <p>Now the widget renders like this:</p>
  
  <ul>
  <li>România</li>
  <li>United States</li>
  <li>France</li>
  </ul>
  
  <p>But I want it to look like this:</p>
  
  <ul>
  <li>Choose a country - The default and disabled option, which shouldn't be validated by the form</li>
  <li>România</li>
  <li>United Stated</li>
  <li>France</li>
  </ul>
  
  <p>How can I do this?</p>