> I actually disagree on this one ... people might deploy Razor in lots of interesting ways (i.e., behind proxies, mapped to fun places in the URL hierarchy etc.) We should therefore ask for the API entrypoint URL in its full glory instead of assuming where on a server it is.

I am fine with the idea of asking for *the complete URL* rather than
just the server and port; if we just ditch the magic that turns
`localhost` into a valid URL, we are good to go IMO.  (Eventually, I
predict a `~/.razorrc` file to allow users to configure this away from
the command line, but for now, just in the environment is fine. :)