tomchristie/django-rest-framework — pull request #1508 by dmitry-mukhin (2014-04-07 16:33:47+00:00)
Title: set Retry-After header when throttled

[RFC 6585](http://tools.ietf.org/html/rfc6585) states that response MAY include a Retry-After header indicating how long to wait before making a new request.
So I have duped `X-Trottle-Wait-Settings` to `Retry-After`.