title: Displaying Http404 parameter in 404.html template
body: <p>If I raise a 404 exception in Django using</p>
  
  <pre><code>raise Http404("Error text")
  </code></pre>
  
  <p>how can I display the Http404 parameter ("Error text" in this case) in my 404.html template?</p>
  
  <p>(I am using the default Django view to handle 404 errors.)</p>