gnu: Add openvpn service.

* gnu/services/vpn.scm: New file.
* gnu/local.mk (GNU_SYSTEM_MODULES): Add it.
* doc/guix.texi (VPN Services): New section.

gnu: tipp10: Adjust phases.

* gnu/packages/education.scm (tipp10)[arguments]: Return #t for
"disable-new-version-check"; fix indentation.

gnu: tipp10: Fix description.

* gnu/packages/education.scm (tipp10)[description]: Do not mention
operating systems; remove hint about language settings.

gnu: xfce4-terminal: Update to 0.8.3.

* gnu/packages/xfce.scm (xfce4-terminal): Update to 0.8.3.

gnu: sbcl-stumpwm: Update to 1.0.0.

* gnu/packages/lisp.scm (sbcl-stumpwm): Update to 1.0.0.

gnu: vc-dwim: Update to 1.8.

* gnu/packages/version-control.scm (vc-dwim): Update to 1.8.
[home-page]: Use https.

gnu: terminology: Update to 1.0.0.

* gnu/packages/enlightenment.scm (terminology): Update to 1.0.0.
[home-page]: Update home-page.

gnu: vim: Update to 8.0.0187.

* gnu/packages/vim.scm (vim, vim-full): Update to 8.0.0187.

gnu: youtube-dl: Update to 2017.01.14.

* gnu/packages/video.scm (youtube-dl): Update to 2017.01.14.

gnu: python-django: Update to 1.10.5.

* gnu/packages/django.scm(python-django): Update to 1.10.5.

gnu: certbot, python-acme: Update to 0.10.1.

These packages should be updated together.

* gnu/packages/tls.scm (certbot, python-acme, python2-acme): Update to 0.10.1.

gnu: python-icalendar: Update to 3.11.2.

* gnu/packages/python.scm (python-icalendar): Update to 3.11.2.

gnu: Add tipp10 touch typing tutor.

* gnu/packages/education.scm (touch10): New variable.
* gnu/packages/patches/tipp10-fix-compiling.patch,
  gnu/packages/patches/tipp10-remove-license-code.patch: New files.
* gnu/local.mk (dist_patch_DATA): Register them.

gnu: xorg: Make font packages bit-reproducible.

* gnu/packages/xorg.scm (%xorg-font-origin): Add 'snippet' and 'modules'
fields.

gnu: xorg: Factorize Xorg font origins.

* gnu/packages/xorg.scm (%xorg-font-origin): New procedure.
(xorg-font-origin): New macro.
(font-adobe100dpi, font-adobe75dpi, font-alias)
(font-arabic-misc, font-cronyx-cyrillic, font-dec-misc)
(font-isas-misc, font-micro-misc, font-misc-cyrillic)
(font-misc-ethiopic, font-misc-misc, font-mutt-misc)
(font-schumacher-misc, font-screen-cyrillic, font-sony-misc)
(font-sun-misc, font-winitzki-cyrillic, font-xfree86-type1): Use it.

gnu: Add ruby-mail.

* gnu/packages/ruby.scm (ruby-mail): New variable.

Signed-off-by: Marius Bakke <mbakke@fastmail.com>

gnu: libxt: Add libxt-guix-search-paths.patch.

Followup to 54d8d0fef1a0224f118dbfad8fceece06d322eab.

* gnu/local.mk (dist_patch_DATA): Add it.

gnu: Add r-sva.

* gnu/packages/bioinformatics.scm (r-sva): New variable.

challenge: Add '--verbose'.

* guix/scripts/challenge.scm (summarize-report): Add #:verbose?
parameter.
[report-hashes]: New procedure.  Use it.
Honor VERBOSE? in the 'match case.
(show-help, %options): Add '--verbose'.
(guix-challenge): Honor it.

challenge: Return comparison reports instead of just discrepancies.

This makes it easier to distinguish between matches, mismatches, and the
various cases of inconclusive reports.

* guix/scripts/challenge.scm (<discrepancy>): Rename to...
(<comparison-report>): ... this.  Add 'result' field.
(comparison-report): New macro.
(comparison-report-predicate, comparison-report-mismatch?)
(comparison-report-match?)
(comparison-report-inconclusive?): New procedures.
(discrepancies): Rename to...
(compare-contents): ... this.  Change to return a list of
<comparison-report>.  Remove calls to 'warning'.
(summarize-discrepancy): Rename to...
(summarize-report): ... this.  Adjust to <comparison-report>.
(guix-challenge): Likewise.
* tests/challenge.scm ("no discrepancies")
("one discrepancy"): Adjust to new API.
("inconclusive: no substitutes")
("inconclusive: no local build"): New tests.