gnu: guile2.0-bash: Use G-expressions.

* gnu/packages/guile-xyz.scm (guile2.0-bash)[arguments]:
Rewrite as G-expressions.

gnu: guile2.0-bash: Remove native-input labels.

* gnu/packages/guile-xyz.scm (guile2.0-bash)[native-inputs]:
Remove input labels.

gnu: guile2.0-bash: Update source & home page URI.

* gnu/packages/guile-xyz.scm (guile2.0-bash)[home-page]: Use working URL.
[source]: Likewise, and don't re-use HOME-PAGE.

gnu: memcached: Update to 1.6.16.

* gnu/packages/databases.scm (memcached): Update to 1.6.16.

gnu: ioquake3: Update to 1.3.6-2.29b0cc3.

* gnu/packages/game-development.scm (ioquake3): Update to 1.3.6-2.29b0cc3.

gnu: ioquake3: Prepare for cross-compilation.

* gnu/packages/game-development.scm (ioquake3)[arguments]: Use CC-FOR-TARGET.

gnu: ioquake3: Deduplicate make flags.

* gnu/packages/game-development.scm (ioquake3)[arguments]:
Honour #:make-flags in the 'install phase.

gnu: ioquake3: Use G-expressions.

* gnu/packages/game-development.scm (ioquake3)[arguments]:
Rewrite as G-expressions.

gnu: ioquake3: Remove input labels.

* gnu/packages/game-development.scm (ioquake3)[inputs]:
Remove input labels.

gnu: Remove ‘open source’ from package descriptions.

Also do some (trivial) editing where appropriate.

* gnu/packages/bioconductor.scm (r-anaquin, r-rcppnumerical)
[description]: Remove superfluous ‘open source’.
* gnu/packages/debian.scm (apt-mirror)[description]: Likewise.
Add @acronym{}.  Drop obscure Ubuntu for famous Trisquel.  Reorder.
* gnu/packages/documentation.scm (scrollkeeper)[description]:
Remove superfluous ‘open systems’.  Keep ‘Open Source’ in standard name.
* gnu/packages/engineering.scm (freecad, cura-engine)[description]:
Remove superfluous ‘open source’ and excessive puffery.
* gnu/packages/firmware.scm (make-opensbi-package)
[synopsis]: Remove ‘Open Source’.  Use @acronym{}.
[description]: Fix first sentence to follow guidelines.  Use @acronym{}.
* gnu/packages/game-development.scm (ioquake3, recastnavigation):
[description]: Remove ‘open source’.
* gnu/packages/graphics.scm (skia)[description]: Likewise.
* gnu/packages/lisp-xyz.scm (sbcl-s-sysdeps)[description]: Likewise.
* gnu/packages/machine-learning.scm (onnx)[description]: Likewise.
Use @acronym{}.
* gnu/packages/ocaml.scm (ocaml-cudf)[description]: Likewise.

gnu: sqlitebrowser: Fix description.

* gnu/packages/databases.scm (sqlitebrowser)[synopsis]: Include more keywords.
[description]: Bring up to snuff.

doc: Fix typos.

* doc/guix.texi: Fix various typos found by translators.

gnu: opam: Update to 2.1.3.

* gnu/packages/ocaml.scm (opam): Update to 2.1.3.

gnu: electron-cash: Update to 4.2.11.

* gnu/packages/finance.scm (electron-cash): Update to 4.2.11.

gnu: perl-class-methodmaker: Build reproducibly.

* gnu/packages/patches/perl-class-methodmaker-reproducible.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add patch.
* gnu/packages/perl.scm (perl-class-methodmaker)[source]: Use patch.

gnu: libnet: Set man page date to built reproducibly.

* gnu/packages/networking.scm (libnet)[argument]: Add 'fix-manpage-date phase.

gnu: directfb: Remove timestamp to build reproducibly.

* gnu/packages/graphics.scm (directfb)[arguments]: Add 'remove-buildtime
  phase.

gnu: diffoscope: Update to 221.

* gnu/packages/diffoscope.scm (diffoscope): Update to 221.

gnu: emacs-modus-themes: Update to 2.6.0.

* gnu/packages/emacs-xyz.scm (emacs-modus-themes): Update to 2.6.0.

gnu: bear: Update to 3.0.20.

* gnu/packages/build-tools.scm (bear): Update to 3.0.20.