This change makes it possible to add multiple SLiM services to an operating
system configuration by setting the new 'display' and 'vt' fields in their
configurations to different values. Each SLiM service will get its own
authfile, logfile, lockfile, and shepherd service, which will start SLiM on a
different tty.
* gnu/services/xorg.scm: Export slim-configuration-display and
slim-configuration-vt.
(<slim-configuration>)[display, vt]: New fields.
(slim-shepherd-service): Refactor let.
[slim.cfg]: Use new fields for setting display_name, xserver_arguments,
authfile, lockfile, and logfile.
[shepherd-service][provision]: Name the shepherd service according to the
value of 'vt'.
[shepherd-service][start]: Delete the right lockfile.
Signed-off-by: Ludovic Courtès <ludo@gnu.org>
61569171d0