gnu: libpsl: Update to 0.20.0.

* gnu/packages/web.scm (libpsl): Update to 0.20.0.

gnu: Use HTTPS for supported freedesktop.org home pages.

* gnu/packages/fontutils.scm (fontconfig)[home-page]: Use HTTPS.
* gnu/packages/freedesktop.scm (python-pyxdg, accountsservice)
(modem-manager, telepathy-mission-control, telepathy-mission-control)
(colord-gtk, desktop-file-utils)[home-page]: Likewise.
* gnu/packages/ghostscript.scm (libspectre)[home-page]: Likewise.
* gnu/packages/glib.scm (dbus, dbus-glib, telepathy-glib)[home-page]:
Likewise.
* gnu/packages/gnome.scm (shared-mime-info, hicolor-icon-theme)
(libxklavier, colord, upower)[home-page]: Likewise.
* gnu/packages/gstreamer.scm (orc, python-gst)[home-page]: Likewise.
* gnu/packages/libcanberra.scm (sound-theme-freedesktop)[home-page]:
Likewise.
* gnu/packages/libreoffice.scm (libexttextcat)[home-page]: Likewise.
* gnu/packages/polkit.scm (polkit-gnome, polkit-gnome)[home-page]:
Likewise.
* gnu/packages/pulseaudio.scm (pavucontrol)[home-page]: Likewise.
* gnu/packages/python.scm (python-dbus)[home-page]: Likewise.
* gnu/packages/xdisorg.scm (startup-notification)[home-page]: Likewise.

gnu: polkit: Update phase & snippet style.

* gnu/packages/polkit.scm (polkit)[source]: End snippet with #t.
[arguments]: Substitute INVOKE for SYSTEM* and end phases with #t.

gnu: perl-xml-libxslt: Update to 1.96.

* gnu/packages/xml.scm (perl-xml-libxslt): Update to 1.96.

gnu: perl-net-smtp-ssl: Update to 1.04.

* gnu/packages/web.scm (perl-net-smtp-ssl): Update to 1.04.

gnu: perl-http-server-simple: Update to 0.52.

* gnu/packages/web.scm (perl-http-server-simple): Update to 0.52.

gnu: dvdstyler: Remove hard-coded version string.

* gnu/packages/cdrom.scm (dvdstyler)[arguments]: Remove a hard-coded
version string from the docbook-xsl search path.

gnu: libdvbpsi: Update to 1.3.2.

* gnu/packages/video.scm (libdvbpsi): Update to 1.3.2.

gnu: tinc: Update to 1.0.33.

* gnu/packages/vpn.scm (tinc): Update to 1.0.33.

gnu: gource: Update to 0.48.

* gnu/packages/version-control.scm (gource): Update to 0.48.

gnu: youtube-dl: Update to 2018.02.22.

* gnu/packages/video.scm (youtube-dl): Update to 2018.02.22.

gnu: libfilezilla: Update to 0.12.1.

* gnu/packages/ftp.scm (libfilezilla): Update to 0.12.1.

gnu: automake: Add 1.16.

* gnu/packages/autotools.scm (automake-1.16): New variable.

build: Require Guile >= 2.0.13.

* README, configure.ac, doc/guix.texi (Requirements): Increase minimum
Guile version from 2.0.9 to 2.0.13.
* config-daemon.ac: Remove use of 'GUIX_CHECK_UNBUFFERED_CBIP'.
* m4/guix.m4 (GUIX_CHECK_UNBUFFERED_CBIP): Remove.
* guix/build/download.scm (current-http-proxy): Remove.
* guix/build/syscalls.scm (%libc-errno-pointer, errno): Remove.
(syscall->procedure): Use #:return-errno unconditionally.
* guix/hash.scm (open-sha256-input-port)[unbuffered]: Remove outdated
comment.
* guix/http-client.scm (when-guile<=2.0.5-or-otherwise-broken): Remove.
<top level>: Remove 'when-guile<=2.0.5-or-otherwise-broken' block.
* guix/scripts/substitute.scm (fetch): Remove 'guile-version>?'
conditional.
* tests/hash.scm (supports-unbuffered-cbip?): Remove.
<top level>: Remove 'test-skip' call.

gnu: python-scandir: Run the test suite.

* gnu/packages/python.scm (python-scandir)[arguments]: Replace CHECK-PHASE.

gnu: python-scandir: Update to 1.7.

* gnu/packages/python.scm (python-scandir): Update to 1.7.
[description]: Mention that the Python3 variant is obsolete.

gnu: python2-pathlib2: Update to 2.3.0.

* gnu/packages/python.scm (python2-pathlib2): Update to 2.3.0.
[propagated-inputs]: Add PYTHON2-SCANDIR.

gnu: python-ipython: Update to 5.5.0.

* gnu/packages/python.scm (python-ipython): Update to 5.5.0.

gnu: python-pickleshare: Run the tests.

* gnu/packages/databases.scm (python-pickleshare)[arguments]: Replace CHECK-PHASE.
[native-inputs]: Add PYTHON-PYTEST.

gnu: python2-pathlib2: Propagate python2-six.

* gnu/packages/python.scm (python2-pathlib2)[native-inputs]: Move to ...
[propagated-inputs] ... here.