bug#16507: [RFC] Add a systemd service file for dealing with emacs --daemon.

[Ulrich Mueller <ulm@gentoo.org>]

>>>>> On Thu, 04 Dec 2014, Rüdiger Sonderfeld wrote:

> On Wednesday 03 December 2014 23:08:29 Ulrich Mueller wrote:
>> Which means that we shall disable installation of the file in
>> Gentoo. (Besides, systemd isn't our default init system ...)

> Multiple versions are indeed an issue. I don't know if the systemd
> folks have a suggestion for that case. But as far as I understand
> the recommendation is indeed to install unit files to the directory
> given by pkg-config.

> The installation directory can of course be changed and you could
> simply point it elsewhere and then have the user copy the unit file
> she wants.

IIUC, a copy of the file is installed with the data-directory (etc/)
anyway? So the file will be available to the user, even if not
installed in the pkgconfig location.

Alternatively, if there is users' demand for it, we (Gentoo) could
add the unit to another package (like app-emacs/emacs-common-gentoo
which contains the desktop files, or app-emacs/emacs-daemon). We try
to keep the number of files installed such at a minimum, though, and
follow upstream's install locations whereever possible.