linux-initrd: Add isofs if necessary.

* gnu/system/linux-initrd.scm (base-initrd): Add isofs.

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.

file-systems: iso9660-uuid->string: Use "-" as separator in the result.

* gnu/build/file-systems.scm (iso9660-uuid->string): Use "-" as separator
in the result.

gnu: beets: Update to 1.4.5.

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

install: Re-add /bin/sh.

Reported by Divan Santana <divan@santanas.co.za>.
/bin/sh had disappeared in commit
387e175492f960d7d86f34f3b2e43938fa72dbf3.

* gnu/system/install.scm (%installation-services): Add
'special-files-service-type' instance.

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.

ui: package->recutlis: Remove duplicated package names in dependencies.

* guix/ui.scm (package->recutils): Add call to 'delete-duplicates' in
'dependencies->recutils'.

store: 'references/substitutes' really caches its result.

Until now the cache was always empty because 'for-each' was passed ITEMS
as its second argument, and ITEMS was the empty list at that point.

* guix/store.scm (references/substitutes): Add 'requested' variable.
Use it as second argument of 'for-each' in base case.

store: 'references/substitutes' save an RPC is the trivial case.

* guix/store.scm (references/substitutes): Save a
'substitutable-path-info' call when MISSING is empty.

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.

guix: git: Stop using libgit2-shutdown.

* guix/git.scm (with-libgit2): Stop calling (libgit2-shutdown) to prevent
segfaults when pointer finalizers are run.

gnu: cd-hit: Update to 4.6.8.

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