gnu: grub-efi: Disable tests on all platforms.

This is a follow-up to 56f0feb6781e3680541d7adc21d6b3b4746a33ca
and 63087721bb54a14dc04ec424474386ae98f7771b, which accidentally
enabled tests for grub-efi on other platforms.

* gnu/packages/bootloaders.scm (grub-efi)[arguments]: Override inherited
tests field and disable on all platforms.

gnu: exim: Update to 4.89.1.

* gnu/packages/mail.scm (exim): Update to 4.89.1.
[source]: Remove patches for fixed CVEs (all of them).
* gnu/packages/patches/exim-CVE-2017-16943.patch: Delete file...
* gnu/packages/patches/exim-CVE-2017-16944.patch: ...as well as this file...
* gnu/packages/patches/exim-CVE-2017-1000369.patch: ...and this file.
* gnu/local.mk (dist_patch_DATA): Remove all of them.

gnu: libgit2: Avoid dependency on cURL.

This reduces the closure size from 225 MiB to 80 MiB, while still
supporting HTTP(S) access.

* gnu/packages/version-control.scm (libgit2)[source](modules, snippet):
New fields.
[inputs]: Remove CURL; add HTTP-PARSER.

gnu: spectrwm: Fix description.

* gnu/packages/wm.scm (spectrwm)[description]: Fix typo and use @dfn.

gnu: ghc-happy: Update to 1.19.8.

* gnu/packages/haskell.scm (ghc-happy): Update to 1.19.8.
[arguments]: Delete; run all tests.

gnu: curl: Update to 7.57.0 [fixes CVE-2017-{8816,8817,8818}].

* gnu/packages/curl.scm (curl): Update replacement to 7.57.0.
(curl-7.56.1): Replace with ...
(curl-7.57.0): ... new variable.

gnu: libtorrent-rasterbar: Update to 1.1.5.

* gnu/packages/bittorrent.scm (libtorrent-rasterbar): Update to 1.1.5.

gnu: grub :Disable tests on aarch64.

* gnu/packages/bootloaders.scm (grub)[arguments]: Add aarch64 to the
architectures where the test suite is not run.

gnu: openconnect: Use only vpnc-scripts.

* gnu/packages/vpn.scm (openconnect)[inputs, arguments]: Substitute
‘vpnc-scripts’ for ‘vpnc’

gnu: vpnc: Use newer vpnc-scripts.

* gnu/packages/vpn.scm (vpnc)[source]: Remove patch.
[inputs]: Remove net-tools and iproute2.  Add vpnc-scripts.
[arguments]: Delete ‘configure’ and ‘wrap-vpnc-script’ #:phases.
Add ‘use-store-paths’ phase.
* gnu/packages/patches/vpnc-script.patch: Delete patch.
* gnu/local.mk (dist_patch_DATA): Remove it.

gnu: Add vpnc-scripts.

* gnu/packages/vpn.scm (vpnc-scripts): New variable.

gnu: grub: Disable tests on ARM platforms.

* gnu/packages/bootloaders (grub): Disable tests on ARM platforms.
Half of the tests are failing on ARM.

gnu: Update r-mutationalpatterns to 1.4.1.

* gnu/packages/bioinformatics.scm (r-mutationalpatterns): Update to 1.4.1.

gnu: ghc-tasty-rerun: Update to 1.1.7.

* gnu/packages/haskell-check.scm (ghc-tasty-rerun): Update to 1.1.7.

gnu: limnoria: Update to 2017.10.01.

* gnu/packages/irc.scm (limnoria): Update to 2017.10.01.

gnu: libxfont@1: Update to 1.5.4 [fixes CVE-2017-16611].

* gnu/packages/xorg.scm (libxfont): Update to 1.5.4.

gnu: libxfont@2: Update replacement to 2.0.3 [fixes CVE-2017-16611].

* gnu/packages/xorg.scm (libxfont2/fixed): Rename to ...
(libxfont2-2.0.3): ... this.  Make public.
[version]: New field.
[source]: Add URI and SHA256.  Remove patches.
(libxfont2)[replacement]: Change LIBXFONT2/FIXED to LIBXFONT2-2.0.3.
* gnu/packages/patches/libxfont-CVE-2017-13720.patch,
gnu/packages/patches/libxfont-CVE-2017-13722.patch: Delete files.
* gnu/local.mk (dist_patch_DATA): Remove them.

gnu: libxcursor: Replace with 1.1.15 [fixes CVE-2017-16612].

* gnu/packages/xorg.scm (libxcursor-1.1.15): New public variable.
(libxcursor)[replacement]: New field.

gnu: optipng: Fix CVE-2017-1000229.

* gnu/packages/image.scm (optipng)[source](patches): New field.
* gnu/packages/patches/optipng-CVE-2017-1000229.patch: New file.
* gnu/local.mk (dist_patch_DATA): Register it.

gnu: Add r-copynumber.

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