services: Add '%facebook-host-aliases'.

* gnu/services/networking.scm (%facebook-host-aliases): New variable.
* doc/guix.texi (Networking Services): Document it.

services: Add 'bitlbee-service'.

* gnu/services/networking.scm (bitlbee-service): New procedure.
* doc/guix.texi (Networking Services): Document it.

services: dhcp-client: Start 'dhclient' in "no wait" mode.

* gnu/services/networking.scm (dhcp-client-service): Pass '-nw' to
  'dhclient'.

services: Add 'dhcp-client-service'.

* gnu/services/networking.scm (dhcp-client-service): New procedure.
* doc/guix.texi (Networking Services): Document it.

services: static-networking-service: Wait for udev, except for loopback.

Reported by DusXMT on #guix.

* gnu/services/networking.scm (static-networking-service): Add
  'requirement' field.  Change 'documentation' to be a string literal.

Merge branch 'master' into core-updates

services: Use system groups where applicable.

* gnu/services/avahi.scm (avahi-service): Add 'system?' field to
  'user-group' form.
* gnu/services/base.scm (guix-service): Likewise.
* gnu/services/dbus.scm (dbus-service): Likewise.
* gnu/services/networking.scm (tor-service): Likewise.

services: Add Tor service.

* gnu/services/networking.scm (tor-service): New procedure.
* doc/guix.texi (Networking Services): Document it.
* build-aux/hydra/demo-os.scm: Use it.  Add TOR and TORSOCKS to
  'packages'.

services: networking: Set interfaces up; delete default route only when needed.

* gnu/services/networking.scm (static-networking-service): Use -i, -A,
  and --up with Inetutils' ifconfig.  Do 'route del -net default' only
  when GATEWAY is true.

services: Provide a 'loopback' service by default.

* gnu/services/networking.scm (static-networking-service): Add
  #:provision parameter; use it.
* gnu/services/base.scm (%base-services): Call
  'static-networking-service' for "lo".

services: Use more Texinfo markup in docstrings.

* gnu/services/base.scm (host-name-service): Use Texinfo markup.
  (mingetty-service): Comment on #:allow-empty-passwords?.  Improve
  markup.
  (syslog-service, guix-service): Use Texinfo markup.
* gnu/services/networking.scm (static-networking-service): Likewise.
* gnu/services/xorg.scm (slim-service): Likewise.

Merge branch 'master' into core-updates

services: networking: Fix typo in static networking service.

* gnu/services/networking.scm (static-networking-service): Use
  $inetutils/bin/ifconfig, not $inetutils/sbin/ifconfig.

services: Rewrite using gexps.

* gnu/services.scm (<service>)[inputs]: Remove.
* gnu/system.scm (links): Remove.
  (etc-directory): Add PASSWD and SHADOW to #:inputs.
  (operating-system-boot-script): Pass ETC to 'dmd-configuration-file'.
  (operating-system-derivation): Remove EXTRAS from the union.
* gnu/system/linux.scm (pam-service->configuration): Rewrite in terms of
  'gexp->derivation'.  Compute the contents on the build side.  Expect
  'arguments' to contain a list of gexps.
  (pam-services->directory): Rewrite in terms of 'gexp->derivation'.
  (unix-pam-service): Change 'arguments' to a list of one gexp.
* gnu/system/shadow.scm (<user-account>)[inputs]: Remove.
  [shell]: Change default value to a gexp.
  (passwd-file): Rewrite in terms of 'gexp->derivation'.  Compute
  contents on the build side.
* gnu/services/base.scm (host-name-service, mingetty-service,
  nscd-service, syslog-service, guix-service): Change 'start' and 'stop'
  to gexps; remove 'inputs' field.
  (guix-build-accounts): Change 'shell' field to a gexp.
* gnu/services/networking.scm (static-networking-service): Change
  'start' and 'stop' to gexps; remove 'inputs' field.
* gnu/services/xorg.scm (slim-service): Likewise.
* gnu/services/dmd.scm (dmd-configuration-file): Expect ETC to be a
  derivation.  Change 'config' to a gexp.  Use 'gexp->file' instead of
  'text-file'.
* doc/guix.texi (Defining Services): Update nscd example with gexps, and
  without 'inputs'.  Add xref to "G-Expressions".

Merge branch 'master' into core-updates

Conflicts:
	gnu-system.am

gnu: Introduce the (gnu services ...) modules.

* gnu/system/dmd.scm: Remove file.  Move contents to...
* gnu/services.scm, gnu/services/base.scm, gnu/services/dmd.scm,
  gnu/services/networking.scm, gnu/services/xorg.scm: ... here.  New
  files.
* gnu/system.scm, gnu/system/vm.scm: Adjust accordingly.
* guix/scripts/system.scm (%user-module): Likewise.
* doc/guix.texi (Using the Configuration System): Likewise.
  (Defining Services): Likewise.