gnu: shflags: Use the GNU-BUILD-SYSTEM.

The TRIVIAL-BUILD-SYSTEM doesn't really save any effort and is actually
slightly longer.

* gnu/packages/version-control.scm (shflags)[build-system: Use
GNU-BUILD-SYSTEM.
[arguments]: Adjust accordingly and prefer INSTALL-FILE over COPY-FILE.

gnu: htop: Fix tree view.

* gnu/packages/patches/htop-fix-process-tree.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.
* gnu/packages/admin.scm (htop)[source]: Use it.

gnu: lpsolve: Update phase style.

* gnu/packages/maths.scm (lpsolve)[arguments]: Use INVOKE and
INSTALL-FILE, and end phases with #t.

gnu: iptables: Edit synopsis & description.

* gnu/packages/linux.scm (iptables)[synopsis, description]: Improve.

gnu: iptables: Update to 1.6.2.

* gnu/packages/linux.scm (iptables): Update to 1.6.2.

gnu: lout: Update phase style.

* gnu/packages/lout.scm (lout)[arguments]: Write phases in-line, use
MODIFY-PHASES syntax, INVOKE, and WITH-DIRECTORY-EXCURSION, and end
phases with #t.  Re-indent the result.

gnu: cook: Update phase style.

* gnu/packages/cook.scm (cook)[arguments]: Use MODIFY-PHASES syntax and
end phase with #t.

gnu: slang: Update to 2.3.1a.

* gnu/packages/slang.scm (slang): Update to 2.3.1a.

gnu: shflags: Set source file name.

* gnu/packages/version-control.scm (shflags)[source]: Use a meaningful
FILE-NAME.

gnu: getmail: Update to 5.5.

* gnu/packages/mail.scm (getmail): Update to 5.5.

gnu: ldc: Add comment.

* gnu/packages/ldc.scm (ldc): Add comment.

gnu: dub: Use invoke.

* gnu/packages/ldc.scm (dub): Use invoke.

gnu: rdmd: Use invoke.

* gnu/packages/ldc.scm (rdmd): Use invoke.

services: slim: Make the logged-in session show up in "w".

* gnu/services/xorg.scm (slim-shepherd-service): Use SESSREG to register X11
session.
* doc/guix.texi (slim-configuration): Document new field "sessreg".

gnu: ldc: Update to 1.7.0.

Fixes recent bootstrap and updates ldc and package manager to match.

* gnu/packages/ldc.scm (ldc-bootstrap): Update to 0.17.4.
[properties]: Add max-slient-time.
[arguments]<#:phases>[patch-phobos]: Update patches (see below).
(ldc): Update to 1.7.0.
(ldc-beta): Delete variable.
[arguments]<#:phases>[patch-phobos]: Update patches (see below).
[arguments]<#:phases>[check]: Use invoke.
(rdmd): Update to 2.077.1.
(dub): Update to 1.7.2.
* gnu/local.mk (dist_patch_DATA): Remove "ldc-disable-tests.patch".
Add "ldc-bootstrap-disable-tests.patch".
Remove "ldc-1.1.0-disable-phobos-tests.patch".
Add "ldc-1.7.0-disable-phobos-tests.patch".
Remove "ldc-1.1.0-disable-dmd-tests.patch".

Co-Authored-By: Danny Milosavljevic <dannym@scratchpost.org>

gnu: nginx: Update to 1.13.9.

* gnu/packages/web.scm (nginx): Update to 1.13.9.

gnu: grub: Run tests against Qemu 2.10.

* gnu/packages/bootloaders.scm (qemu-minimal-2.10): New variable.
(grub)[native-inputs]: Replace QEMU-MINIMAL with QEMU-MINIMAL-2.10.

gnu: qemu: Update to 2.11.1.

* gnu/packages/patches/qemu-CVE-2017-15038.patch,
gnu/packages/patches/qemu-CVE-2017-15289.patch: Delete files.
* gnu/local.mk (dist_patch_DATA): Remove them.
* gnu/packages/virtualization.scm (qemu): Update to 2.11.1
[source](patches): Remove.

gnu: freetype: Fix CVE-2018-6942.

* gnu/packages/patches/freetype-CVE-2018-6942.patch: New file.
* gnu/local.mk (dist_patch_DATA): Register it.
* gnu/packages/fontutils.scm (freetype)[replacement]: New field.
(freetype/fixed): New variable.

gnu: python-pyopenssl: Update to 17.5.0.

* gnu/packages/python-crypto.scm (python-pyopenssl): Update to 17.5.0.