title: Negation or exclude filter in Django REST Framework
body: <p>I've used Django REST Framework for quite a while now, but have come across a situation where I need to retrieve everything but a known relation in an API view. After looking through the documentation again, I cannot see any built-in mechanism to achieve this. I realize I can override <code>get_queryset()</code> in my ListView and parse custom URL query parameters and then do the filtering, but I'm curious if anyone else has a more elegant solution?</p>
  
  <p><strong>Update</strong></p>
  
  <p>After a little more research, this seems to be more of a django-filter question, and I cannot find mention of any exclude functionality. I did find this:</p>
  
  <p><a href="https://bitbucket.org/mjs7231/django-rest-framework-filtering" rel="noreferrer">https://bitbucket.org/mjs7231/django-rest-framework-filtering</a></p>
  
  <p>which does provide excluding values from the results.</p>