* Move `hostname` and `root` into a settings submodule with a freeform
type, allowing users to also use options not known to the NixOS
service. Compatibility with a warning for the renamed options is also
trivial to achieve.
* `port` stays where it is as we don't actually use the `port` option of
spacecookie to set up the socket, but only to inform spacecookie about
the port we have set in the `systemd.socket` file, this makes more
sense. Additionally the configuration of the listening port and
address change in the next spacecookie release — we can dodge this
issue altogether by doing our own thing, but I'm interested to hear
opinions on this.
To ensure that this is not misconfigured, we add an assertion for
the port option.
* Add an assertion for `user` in settings which has no effect the way
we are starting spacecookie as it wouldn't be able to call setuid.
The message also explains how a specific user can be used with
spacecookie if desired.
* Use proper gopher urls
* The client vms name is also controlled in a single place now
* fileContent holds the precise file content now
* wait for the spacecookie unit instead of the port
* avoids sending an empty request
* since spacecookie is a notify service it only is fully started when
the socket has been set up.
