bug#24218: 25.1.50; server-name, server-socket-dir and daemon start through, systemd socket

[Eli Zaretskii]

> Cc: matthew@mattleach.net, 24218@debbugs.gnu.org, lomov.vl@gmail.com
> From: Paul Eggert <eggert@cs.ucla.edu>
> Date: Sun, 7 Jan 2018 20:24:57 -0800
> 
> Eli Zaretskii wrote:
> >    . internal--external-sockname should be documented in the ELisp
> >      manual (a better name that doesn't use both "internal" and
> >      "external" will be appreciated)
> 
> The "internal--" prefix is intended to mean "for Emacs internal use only"

That's exactly why I made the comment about the name: IMO, this
variable's purpose is inconsistent with its being for internal use
only.