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.

gnu: Removed unused module import from (gnu packages gimp).

* gnu/packages/gimp.scm (define-module): Remove (gnu packages imagemagick).

gnu: python2-dogtail: Fix typo in synopsis.

* gnu/packages/python.scm (python2-dogtail)[synopsis]: Remove 'ZERO
WIDTH SPACE' (U+200B) character.

gnu: audacity: Update to 2.1.2.

* gnu/packages/audacity.scm (audacity): Update to 2.1.2.
[source](uri): Update source URL.
[inputs]: Replace wxwidgets-2 with wxwidgets-gtk2.
[native-inputs]: Add gettext-minimal.

gnu: Add lchat.

* gnu/packages/suckless.scm (lchat): New variable.

Signed-off-by: Leo Famulari <leo@famulari.name>

gnu: Add libutf.

* gnu/packages/suckless.scm (libutf): New variable.

Signed-off-by: Leo Famulari <leo@famulari.name>

gnu: Add colors.

* gnu/packages/suckless.scm (colors): New variable.

Signed-off-by: Leo Famulari <leo@famulari.name>

gnu: Add fortify-headers.

* gnu/packages/suckless.scm (fortify-headers): New variable.

Signed-off-by: Leo Famulari <leo@famulari.name>

gnu: Add human.

* gnu/packages/suckless.scm (human): New variable.

Signed-off-by: Leo Famulari <leo@famulari.name>

gnu: Add noice.

* gnu/packages/suckless.scm (noice): New variable.

Signed-off-by: Leo Famulari <leo@famulari.name>

gnu: Add prout.

* gnu/packages/suckless.scm (prout): New variable.

Signed-off-by: Leo Famulari <leo@famulari.name>

gnu: Add sbm.

* gnu/packages/suckless.scm (sbm): New variable.

Signed-off-by: Leo Famulari <leo@famulari.name>

gnu: Add skroll.

* gnu/packages/suckless.scm (skroll): New variable.

Signed-off-by: Leo Famulari <leo@famulari.name>

licenses: Add wtfpl2.

* guix/licenses.scm (wtfpl2): New variable.

Signed-off-by: Leo Famulari <leo@famulari.name>

gnu: Add spoon.

* gnu/packages/suckless.scm (spoon): New variable.

Signed-off-by: Leo Famulari <leo@famulari.name>