Copy everything from how the issuer does it.

Just require hostName and domain instead of an extra publicIPv4 option.  Leave
behind a similar option, `publicAddress`, just in case it needs to be
overridden at some point, but stop supplying a value for it anywhere.

More flexibility and less dots in config files.
Implements #65.

Also configure a new value on the staging grid

Also put library code in a library directory