tests: Create a copy-on-write image instead of copying eagerly.

* gnu/tests/install.scm (qemu-command/writable-image): Invoke 'qemu-img
-o backing_file' instead of calling 'copy-file'.

gnu: hdf5: Update to 1.8.18 [fixes CVE-2016-{4330,4331,4332,4333}].

* gnu/packages/maths.scm (hdf5): Update to 1.8.18.
[source]: Add alternate URL.

services: nginx: Join strings with spaces.

* gnu/services/web.scm (config-domain-strings, config-index-strings):
Use "string-join" to join strings with spaces.

gnu: gcj: Conditionally apply patch for armhf.

* gnu/packages/gcc.scm (gcj)[source]: Inherit from "gcc" package.
[native-inputs]: Conditionally add arm-patch.
[arguments]: Conditionally add phase "apply-arm-patch".

gnu: borg: Fix the test suite.

* gnu/packages/backup.scm (borg)[arguments]: Use
add-installed-pythonpath and disable tests related to FUSE.

gnu: git: Update to 2.11.0.

* gnu/packages/version-control.scm (git): Update to 2.11.0.

services: Add 'cuirass-service'.

* gnu/services/cuirass.scm: New file.
* gnu/local.mk (GNU_SYSTEM_MODULES): Add it.
* doc/guix.texi (Continuous integration): New node.

gnu: Add Cuirass.

* gnu/packages/ci.scm (cuirass): New variable.

Co-authored-by: Jan Nieuwenhuizen <janneke@gnu.org>

gnu: guix-0.11.0: Add guile-ssh to inputs.

* gnu/packages/package-management.scm (guile-ssh)[inputs]: Add
  guile-ssh.
  [arguments]: Add guile-ssh to GUILE_LOAD_PATH.

gnu: frescobaldi: Disable tests.

* gnu/packages/music.scm (frescobaldi)[arguments]: Disable tests.

gnu: Add zzuf

* gnu/packages/debug.scm (zzuf): New variable.

gnu: libxfont: Update to 1.5.2.

* gnu/packages/xorg.scm (libxfont): Update to 1.5.2.

gnu: gphoto2, libgphoto2: Use libjpeg-turbo.

* gnu/packages/photo.scm (gphoto2, libgphoto2)[inputs]: Add libjpeg-turbo.

gnu: spice: Use libjpeg-turbo instead of libjpeg.

* gnu/packages/spice.scm (spice)[inputs]: Use libjpeg-turbo as suggested
during the build.

gnu: icecat: Use libjpeg-turbo instead of bundled libjpeg.

* gnu/packages/gnuzilla.scm (icecat)[source]: Remove bundled libjpeg, which
is actually libjpeg-turbo.
[inputs]: Add libjpeg-turbo.
[arguments]: Use it.

gnu: Add libjpeg-turbo.

* gnu/packages/image.scm (libjpeg-turbo): New variable.

gnu: kauth: Fix cmake macros to be used by other packages.

* gnu/packages/kde-framework.scm (kauth)[phases]: New phase
  fix-cmake-install-paths.

gnu: extra-cmake-modules: Always install into /lib and not into /lib64.

* gnu/packages/kde-frameworks.scm (extra-cmake-modules)[phases]:
  New phase fix-lib-path.

gnu: Add ksyntaxhighlighting.

* gnu/packages/kde-frameworks.scm (ksyntaxhighlighting): New variable.

gnu: Update kde-frameworks to 5.28.

* gnu/packages/kde-frameworks.scm (kpackage): Update to 5.28.1
  (extra-cmake-modules, attica, bluez-qt, breeze-icons, kapidox,
  karchive, kcodecs, kconfig, kcoreaddons, kdbusaddons, kdnssd,
  kguiaddons, ki18n, kidletime, kitemmodels, kitemviews, kplotting,
  kwayland, kwidgetsaddons, kwindowsystem, modemmanager-qt,
  networkmanager-qt, oxygen-icons, solid, sonnet, threadweaver, kauth,
  kcompletion, kcrash, kdoctools, kfilemetadata, kimageformats,
  kjobwidgets, knotifications, kpty, kunitconversion, baloo,
  kactivities, kactivities-stats, kbookmarks, kcmutils,
  kconfigwidgets, kdeclarative, kded, kdesignerplugin, kdesu,
  kemoticons, kglobalaccel, kiconthemes, kinit, kio, knewstuff,
  knotifyconfig, kparts, kpeople, krunner, kservice, ktexteditor,
  ktextwidgets, kwallet, kxmlgui, kxmlrpcclient, plasma-framework,
  frameworkintegration): Update to 5.28.0