HTTP status code 301 is for a permanent redirect, which these are not.
Although 302 would work here in most browsers, it would not follow the
HTTP spec, so instead we use 303 which has a clearly and consistently
defined behavior in response to a POST or PUT request.
This is a better way to do things since we were customizing middleware
and everything anyway. It's also necessary in order to avoid pulling in
the default Goji -bind flag: https://github.com/zenazn/goji/issues/47
This should protect against cross-site request forgery without the need
for cookies. It continues to allow requests with Linx-Delete-Key,
Linx-Expiry, or Linx-Randomize headers as these will not be set in the
case of cross-site requests.
