[MERGE] Authentication Ring spec

[Martin Pool]

> I saw announce of py-bcrypt in Daily Python:
> http://www.mindrot.org/projects/py-bcrypt/
> Windows version is available.
>
> Just for case, maybe it's interested/useful for implementation
> of auth ring.

This seems to be for hashing passwords to put them into a passwd-like
file on a server.  I don't think we can use it for the auth ring
because the original password cannot be recovered, but we could use it
if we do builtin authentication in the server (which would be a
separate project.)

-- 
Martin