Merge from vendor branch TNF:

Merge from vendor branch TNF:
Django REST framework is a lightweight REST framework for Django, that aims to
make it easy to build well-connected, self-describing RESTful Web APIs.

Features:
* Automatically provides an awesome Django admin style browse-able
  self-documenting API.
* Clean, simple, views for Resources, using Django's new class based views.
* Support for ModelResources with out-of-the-box default implementations and
  input validation.
* Pluggable parsers, renderers, authentication and permissions - Easy to
  customise.
* Content type negotiation using HTTP Accept headers.
* Optional support for forms as input validation.
* Modular architecture - MixIn classes can be used without requiring the
  Resource or ModelResource classes.