A Port Change notification's `Hosts:` line listed a port's apex domains
and hostnames together. It now has a `Domains:` line and a `Hostnames:`
line, and leaves out one that would name nothing. A name is a domain
when it is a configured domain, the rule record notifications already
use to start `Domain:` or `Hostname:`; that rule is now one method,
isDomain, which both use. The port entries saved in the state are
unchanged. README describes the new lines.
Model: opus-5-5