First cut of /api/v0/user/get404
First cut of /api/v0/user/get404

The idea behind this is that we can use basic auth to get auth token,
and then use auth token for all other RESTful API invocations.

This is of course a kludge-y hack, but OAuth and JWT are complicated;
and the parts where clients obtain tokens are underspecified anyway.

sajith/betty-web