gnu: guix: Really skip "pivot-root" test.

This is a followup to fe9bdb581e6c4a62795f4ced6f4a5a8eab1a34e4 (which
introduced 'test-equal' for the "pivot-root" test) and to
198eac2bca075d0e71e504f1e8c46fddc62171bb (which updated the regexps for
skipped tests.)

* gnu/packages/package-management.scm (guix-0.12.0)[arguments]: In
'disable-container-tests' phase, add "test-equal" to the regexp, so that
"pivot-root" is really skipped.

gnu: guix: Update development snapshot.

* gnu/packages/package-management.scm (guix-devel): Update to b291b327.

gnu: linux-libre: Avoid invalid "kconfig" input on armhf and mips64el.

This fixes a bug whereby:

  guix build linux-libre -s armhf-linux

would fail with:

  guix build: error: gnu/packages/linux.scm:231:2: package `linux-libre-4.8.15' has an invalid input: ("kconfig" #f)

This led 'tests/guix-system.sh' to fail.

* gnu/packages/linux.scm (make-linux-libre)[native-inputs]: Never add #f
as a "kconfig" input.

gnu: guix: Update development snapshot.

* gnu/packages/package-management.scm (guix-devel): Update to c8e2219c.
(guix): Set to GUIX-DEVEL.

gnu: guix: Update to 0.12.0.

* gnu/packages/package-management.scm (guix-0.11.0): Rename to...
(guix-0.12.0): ... this.  Adjust users.
(guix): Set to GUIX-0.12.0.

build: Delete all the .service and .conf files upon 'make clean'.

* nix/local.mk (CLEANFILES): Define to add $(nodist_systemdservice_DATA)
and $(nodist_upstartjob_DATA).

doc: Replace fingerprint of OpenPGP signing key.

* doc/guix.texi (OPENPGP-SIGNING-KEY-ID): Update to Ricardo's key for
the 0.12.0 release.

build: Bump version number.

* configure.ac: Change version to 0.12.0.

Update NEWS.

Co-authored-by: Ludovic Courtès <ludo@gnu.org>

services: cuirass: Add Cuirass to the system profile.

* gnu/services/cuirass.scm (cuirass-service-type): Extend
PROFILE-SERVICE-TYPE.

services: cuirass: Add 'cuirass' field.

* gnu/services/cuirass.scm (<cuirass-configuration>)[cuirass]: New
field.
(cuirass-shepherd-service): Honor it.
* doc/guix.texi (Continuous Integration): Document it.

gnu: cuirass: Make sure 'cuirass' has 'evaluate' in $PATH.

* gnu/packages/ci.scm (cuirass)[arguments]: Add OUT/bin to 'PATH'.

services: cuirass: Create the database directory.

* gnu/services/cuirass.scm (cuirass-activation): Create the database
directory for CONFIG.

gnu: Fix load-extension path in packaging of guile-ncurses.

* gnu/packages/guile.scm (guile-ncurses) [arguments]: Install shared object before
attempting to build the package.  Patch load-extension path before building instead
of after.

gnu: argon2: Update to 20161029.

* gnu/packages/password-utils.scm (argon2): Update to 20161029.

gnu: cppcheck: Update to 1.76.1.

* gnu/packages/check.scm (cppcheck): Update to 1.76.1.

gnu: hunspell: Add missing perl dependency.

* gnu/packages/libreoffice.scm (hunspell)[inputs]: Add perl dependency
for ispellaff2myspell.

gnu: hunspell: Update to 1.5.4.

* gnu/packages/libreoffice.scm (hunspell): Update to 1.5.4.
[source]: Add a file-name.

gnu: Add Ancient Greek Aspell dictionary.

* gnu/packages/aspell.scm (aspell-dict-grc): New variable.

gnu: aspell-dictionary: Use ‘modify-phases’ syntax.

* gnu/packages/aspell.scm (aspell-dictionary)[arguments]: Use
‘modify-phases’.