title: Force django's {% static %} to fail silently
body: <p>I'm using a custom static file storage:</p>
  
  <pre><code>class StaticFilesStorage(CachedFilesMixin, S3BotoStorage):
      pass
  </code></pre>
  
  <p>(the CachedFilesMixin is for cache busting).</p>
  
  <p>My problem is that when I have in my template <code>{% static "file_that_does_not_exist.jpg" %}</code> the template isn't rendered and I get an exception</p>
  
  <pre><code>ValueError: The file 'file_that_does_not_exist.jpg' could not be found with &lt;StaticFilesStorage object at 0x03AE4C70&gt;.
  </code></pre>
  
  <p>It fails because the file isn't on S3 so S3BotoStorage can't serve it but it means that if for example my logo.jpg file is missing for some reason then the entire website goes down and that's not good..</p>
  
  <p>Is there a way to force <code>{% static %}</code> to fail silently?</p>