gnu: Add emacs-emamux.

* gnu/packages/emacs.scm (emacs-emamux): New variable.

Signed-off-by: 宋文武 <iyzsong@member.fsf.org>

gnu: gcr: Enable working tests.

* gnu/packages/patches/gcr-disable-failing-tests.patch,
gnu/packages/patches/gcr-fix-collection-tests-to-work-with-gpg-21.patch:
New files.
* gnu/local.mk (dist_patch_DATA): Add patches.
* gnu/packages/gnome.scm (gcr)[source]: Use patches.
[arguments]: Enable tests.

gnu: xfce: Propagate search paths of 'xfce4-panel'.

* gnu/packages/xfce.scm (xfce)[native-search-paths]: New field.

gnu: Add emacs-sparql-mode.

* gnu/packages/emacs.scm (emacs-sparql-mode): New variable.

gnu: Switch guile-cairo and dependents to Guile 2.2 again.

Fixes <https://bugs.gnu.org/27551>.
Reported by Leo Famulari <leo@famulari.name>.

This reinstates the following commits:

  e3ddb1e83 * gnu: guile-cairo: Switch to Guile 2.2.
  ae5c6ef39 * gnu: guile-gnome: Update to 2.16.5.
  0fd8013fc * gnu: guile-rsvg: Update to commit 05c6a2fd.
  66b9183c4 * gnu: guile-lib: Switch to Guile 2.2.

and adds the following changes:

* gnu/bootloader/grub.scm (svg->png): Add 'package->derivation' call for
GUILE-2.2.  Pass #:guile-for-build to 'gexp->derivation'.
* gnu/build/svg.scm (svg->png): Add 'em' and 'ex' to the 'let-values'
form to account for all the values returned by
'rsvg-handle-get-dimensions', which Guile 2.2 does not truncate.

gnu: Add toxic.

* gnu/packages/messaging.scm (toxic): New variable.

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

gnu: emacs-guix: Update to 0.3.2.

* gnu/packages/emacs.scm (emacs-guix): Update to 0.3.2.
[arguments]: Add '--with-guix-site-ccache-dir' configure flag, as Guix
installs its .go files separately nowadays.

gnu: beets: Update to 1.4.5.

* gnu/packages/music.scm (beets): Update to 1.4.5.

gnu: python-vobject: Update to 0.9.5.

* gnu/packages/python.scm (python-vobject, python2-vobject): Update to 0.9.5.

gnu: vdirsyncer: Update to 0.16.0.

* gnu/packages/dav.scm (vdirsyncer): Update to 0.16.0.
[license]: Change to bsd-3.

gnu: ovmf: Fix build on x86_64.

This is a follow-up to 2eb95ade8f08bfd418b1470f1093c5b4bf2332ee.

* gnu/packages/firmware.scm (ovmf)[arguments]: Fix the syntax used when
following the x86_64 fork of the arguments.

gnu: font-google-noto: Update to 20170403.

* gnu/packages/fonts.scm (font-google-noto): Update to 20170403.
[source]: Update source uri.

gnu: font-gnu-unifont: Update to 10.0.03.

* gnu/packages/fonts.scm (font-gnu-unifont): Update to 10.0.03.
[properties]: Add 'upstream-name' to ease updates.

Revert "gnu: guile-lib: Switch to Guile 2.2."

This reverts commit 66b9183c4f634d9b2ae41176e4eddf0ebb218532.

Revert "gnu: guile-rsvg: Update to commit 05c6a2fd."

This reverts commit 0fd8013fcaafa9f53c7e304b2573c0314471df89.

Revert "gnu: guile-gnome: Update to 2.16.5."

This reverts commit ae5c6ef39378a6fa1f6bf06e8c7f50ab190c485d.

Revert "gnu: guile-cairo: Switch to Guile 2.2."

This commit caused the build of grub-image.png to fail, prevent the
build of grub.cfg and reconfiguring of GuixSD:

<https://bugs.gnu.org/27551>

This reverts commit e3ddb1e83296c10338d35bc687772242b2f5eac6.

gnu: guile-git: Update source URL.

* gnu/packages/guile.scm (guile-git)[source]: Update URL.

gnu: cd-hit: Update to 4.6.8.

* gnu/packages/bioinformatics.scm (cd-hit): Update to 4.6.8.

gnu: bwa: Update to 0.7.15.

* gnu/packages/bioinformatics.scm (bwa): Update to 0.7.15.