title: Set default value of Symfony 2 form field in Twig
body: <p>Is it possible to set default value of input field in Twig ?</p>
  
  <p>I am rendering form row with:</p>
  
  <pre><code>{{ form_widget(form.title) }}
  </code></pre>
  
  <p>I want to be able to set default value like:</p>
  
  <pre><code>{{ form_widget(form.title, {data : 'Default title'}) }}
  </code></pre>
  
  <p>Is it even possible ?</p>