gnu: Add python-xopen.

* gnu/packages/python.scm (python-xopen, python2-xopen): New variables.

gnu: linux-libre: Update to 4.8.15.

* gnu/packages/linux.scm (%linux-libre-version, %linux-libre-hash)
(linux-libre): Update to 4.8.15.

Revert "gnu: linux-libre: Update to 4.9."

This reverts commit 5a3849443ac8bdcffea0376b3c7efa30688c10bb.

Module loading is broken on i686 with some configurations, including our
default configuration.  See <https://bugs.gnu.org/25231>.

gnu: kdbusaddons: Embed kinit store dir, avoid dependency cycles.

kdbusaddons needs to know the location of the kdeinit5 executable,
provided by kinit. kinit depends on kdbusaddons, so we add bootstrap
versions of all packages in the dependency chain from kinit to
kdbusaddons to avoid cyclic dependencies.

* gnu/packages/kde-frameworks.scm (kinit-bootstrap,
  kdbusaddons-bootstrap): New variables.
  (kdbusaddons)[inputs]: Add kinit-bootstrap.
  [source,arguments]: Add patch and substitution to embed
  kinit-bootstrap's store directory in the code.
* gnu/packages/patches/kdbusaddons-kinit-file-name.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

gexp: Slightly simplify 'gexp-inputs'.

* guix/gexp.scm (gexp-inputs)[add-reference-inputs]: Remove unneeded
'if' in the non-native nested gexp case.

gexp: Native inputs of nested gexps are properly accounted for.

Previously, 'gexp-native-inputs' would not return the native inputs of
nested gexps.  For example, this:

  (gexp-native-inputs #~(foo #$#~(bar #+coreutils)))

would return '().

* guix/gexp.scm (gexp-inputs)[add-reference-inputs]: In the
non-recursive cases, check whether N? and NATIVE? are the same, and act
accordingly.
[native-input?]: Remove.
Fold over all of (gexp-references exp).
* tests/gexp.scm ("ungexp + ungexp-native, nested, special mixture"):
New test.
* tests/gexp.scm ("input list splicing + ungexp-native-splicing"): Pass
 #:native? #t to 'gexp-input'.

services: Use 'file-append' in more places.

* gnu/services/avahi.scm (avahi-shepherd-service): Use #$(file-append x y)
instead of (string-append #$x y).
* gnu/services/base.scm (unicode-start)
(console-keymap-service-type, console-font-shepherd-services)
(mingetty-shepherd-service, nscd-shepherd-service)
(hydra-key-authorization, guix-shepherd-service)
(guix-publish-shepherd-service, udev-shepherd-service)
(gpm-shepherd-service, <kmscon-configuration>)
(kmscon-service-type): Likewise.
* gnu/services/shepherd.scm (shepherd-boot-gexp): Likewise.

doc: Mention 'grub' field of 'grub-configuration'.

* doc/guix.texi (GRUB Configuration): Add 'grub' field.

doc: Make 'guix pull' more visible.

Suggested by Dave Love <fx@gnu.org>.
Fixes <http://bugs.gnu.org/25139>.

* doc/guix.texi (Installation): Mention 'guix pull'.
(Proceeding with the Installation): Mention updates with 'guix pull' and
'guix system reconfigure'.
(Invoking guix pull): Add "updating" to the concept index.

doc: Mention 'swapon'.

Suggested by David Braun <Guix-box@snkmail.com>
at <https://lists.gnu.org/archive/html/guix-devel/2016-12/msg00744.html>.

* doc/guix.texi (Preparing for Installation): Add 'swapon'.

gnu: openssh: Update to 7.4p1.

* gnu/packages/ssh.scm (openssh): Update to 7.4p1.
[source]: Remove 'openssh-memory-exhaustion.patch'.
* gnu/packages/patches/openssh-memory-exhaustion.patch: Delete file.
* gnu/local.mk (dist_patch_DATA): Remove it.

gnu: samba: Update to 4.5.3 [fixes CVE-2016-{2123,2125,2126}].

* gnu/packages/samba.scm (samba): Update to 4.5.3.

nls: Update 'fr' translation.

nls: Update 'da' package translation.

nls: Update 'pt_BR' translation.

nls: Update 'da' translation.

gnu: pcsc-lite: Update to 1.8.19.

* gnu/packages/security-token.scm (pcsc-lite): Update to 1.8.19.

gnu: hurd-headers: Update to 0.9.

* gnu/packages/hurd.scm (hurd-headers): Update to version 0.9.

gnu: mig: Update to 1.8.

* gnu/packages/hurd.scm (mig): Update to version 1.8.

gnu: gnumach-headers: Update to 1.8.

* gnu/packages/hurd.scm (gnumach-headers): Update to version 1.8.