title: Django permission_required error message?
body: <p>I've added this decorator to one of my views</p>
  
  <pre><code>@permission_required('codename')
  </code></pre>
  
  <p>When a user visits that page and doesn't have the required permissions, he is redirected the login page, but it doesn't really tell him <em>why</em> he's been redirected there. Worse yet, if he logs in, and <em>still</em> doesn't have the permissions, he's going to be completely clueless as to why he can't access that page!</p>
  
  <p>Isn't there a way I can tap into the messages framework and post an error at the same time?</p>