services: certbot: Allow to set a deploy hook.

* doc/guix.texi (Certificate Services): Document it.
* gnu/services/certbot.scm (<certificate-configuration>, certbot-command): Add
it.

services: certbot: Add verbosity.

The certificate name wasn't displayed if it wasn't being renewed.

* gnu/services/certbot.scm (certbot-command): Print certificate name before
running the associated command.

services: certbot: Allow to set RSA key size.

* doc/guix.texi (Certificate Services): Document it.
* gnu/services/certbot.scm (<cerbot-configuration>, certbot-command,
certbot-activation, certbot-nginx-server-configurations): Add it.

services: certbot: Associate one certificate with several domains.

* doc/guix.texi (Certificate Services): Document <certificate-configuration>,
the change from domains to certificates and the fact that their path is now
derived from their name.
* gnu/services/certbot.scm (<certificate-configuration>): Add and export it.
(certbot-configuration, certbot-command, certbot-activation,
certbot-nginx-server-configurations, certbot-service-type): Replace 'domains'
with 'certificates'.
(certbot-nginx-server-configurations): Use only one nginx-server-configuration
and use all certificate domains as the server-name.

services: certbot: Get certbot to run non-interactively.

* doc/guix.texi (Certificate Services): Add email field and link to the ACME
Subscriber Agreement.
* gnu/services/certbot.scm (<certbot-configuration>, certbot-command,
certbot-activation, certbot-nginx-server-configurations): Add email field.
(certbot-command): Add '-n' and '--agree-tos' options.
(certbot-service-type): Remove default-value.

services: certbot: Refactor certbot command.

* gnu/services/certbot.scm (certbot-renewal-jobs, certbot-activation):
Refactor common code into certbot-command.

services: certbot: Rename 'host' to 'domain'.

* doc/guix.texi (Certificate Services): Rename 'host' to 'domain'.
* gnu/services/certbot.scm (<certbot-configuration>, certbot-renewal-jobs,
certbot-activation, certbot-nginx-server-configurations,
certbot-service-type): Rename 'host' to 'domain'.

services: certbot: Fix indentation.

* gnu/services/certbot.scm (certbot-activation): Fix indentation.

services: certbot: Run certbot twice a day at a random minute.

* doc/guix.texi (Certificate Services): Document it.
* gnu/services/certbot.scm (certbot-renewal-jobs): Change job's time
specification.

services: certbot: Listen on IPv6.

* gnu/services/certbot.scm (certbot-nginx-server-configurations): Listen on
IPv6 too.

services: slim: Make the logged-in session show up in "w".

* gnu/services/xorg.scm (slim-shepherd-service): Use SESSREG to register X11
session.
* doc/guix.texi (slim-configuration): Document new field "sessreg".

services: console-font: Don't emit the IUTF8 console code.

Fixes <https://bugs.gnu.org/30505>.

* gnu/services/base.scm (unicode-start): Remove 'display' call to FD for
"\x1b%G" console code.

services: avahi: Publish '_workstation._tcp' by default.

This reverts to the behavior of avahi-daemon prior to Avahi 0.7 (commit
550f4509acf2c0f67882260414b0bb2843e07465).

* gnu/services/avahi.scm (<avahi-configuration>)[publish-workstation?]:
New field.
(configuration-file): Honor it.

services: avahi: Read PID file from /run.

* gnu/services/avahi.scm (%avahi-activation, avahi-shepherd-service):
Use /run/avahi-daemon/ instead of /var/run/avahi-daemon/.  This was the
case since the switch to Avahi 0.7 (commit
550f4509acf2c0f67882260414b0bb2843e07465).

Merge branch 'master' into core-updates

services: xorg: Import (ice-9 rdelim).

* gnu/services/xorg.scm (xinitrc): Import (ice-9 rdelim).

Merge branch 'master' into core-updates

services: mingetty: Move tty optionality to agetty.

Follow-up to 5a9902c8acd63916c6c80cf3c61be6ee814b7e3d.

* gnu/services/base.scm (mingetty-shepherd-service): Move tty optionality check to...
(agetty-shepherd-service): ...here.

services: agetty: Add agetty instance to base services. Make its tty optional.

* gnu/services/base.scm (%base-services): Instantiate agetty-service.
(default-serial-port): New variable.
(agetty-shepherd-service): Make tty optional, default to the above.
* doc/guix.texi (agetty-configuration): Update "tty" documentation.
* gnu/system/install.scm (agetty-default-service): Delete variable.
(embedded-installation-os): Remove agetty-default-service instance.
Add "console" kernel-argument.

gnu: nss-mdns: Update to 0.12.0.

* gnu/packages/avahi.scm (nss-mdns): Update to 0.12 + patch.
(nss-mdns-0.10.0): Remove.
* gnu/services/avahi.scm (avahi-service-type): Use NSS-MDNS again.