tests: "basic" test loads (guix …) modules from the right place.

This is a followup to 7561881f2a5d2dc463c24713745eca03e67044bf.

* gnu/tests/base.scm (run-basic-test)["/run/current-system is a GC
root"]: Remove 'set!' statements, add 'add-to-load-path' statement for
GUIX.

tests: Strengthen GC root test.

* gnu/tests/base.scm (run-basic-test)["/run/current-system is a GC
root"]: Check for a specific return value, 'success!.

gnu: reptry: Fix build.

* gnu/packages/patches/reptyr-fix-gcc-7.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add new patch.
* gnu/packages/screen.scm (reptyr): Use patch.

gnu: postgresql: Update to 9.6.3 [fixes CVE-2017-{7484,7485,7486}].

* gnu/packages/databases.scm (postgresql): Update to 9.6.3.

gnu: Add lierolibre.

* gnu/packages/patches/lierolibre-check-unaligned-access.patch,
gnu/packages/patches/lierolibre-is-free-software.patch,
gnu/packages/patches/lierolibre-remove-arch-warning.patch,
gnu/packages/patches/lierolibre-try-building-other-arch.patch,
gnu/packages/patches/lierolibre-newer-libconfig.patch: New files.
* gnu/local.mk (dist_patch_DATA): Add them.
* gnu/packages/games.scm (lierolibre): New variable.

gnu: openvpn: Update to 2.4.2 [fixes CVE-2017-7478, CVE-2017-7479].

* gnu/packages/vpn.scm (openvpn): Update to 2.4.2.

gnu: rocksdb: Disable tests on 32-bit systems.

* gnu/packages/databases.scm (rocksdb)[arguments]: Make #:tests? conditional.
Delete unnecessary 'build' phase. Move portability environment variable
before check phase.

gnu: cryptsetup: Update to 1.7.5.

* gnu/packages/cryptsetup.scm (cryptsetup): Update to 1.7.5.

gnu: kbd: Set home page to kbd-project.org.

* gnu/packages/linux.scm (kbd)[home-page]: Update.

gnu: psmisc: Update to 22.21.

* gnu/packages/linux.scm (psmisc): Update to 22.21.
[home-page]: Update.

gnu: proot: Add statically-linked variant.

* gnu/packages/linux.scm (proot-static): New variable.

gnu: talloc: Add static variant.

* gnu/packages/samba.scm (talloc/static): New variable.

gnu: emacs-ag: Propagate the-silver-searcher.

This allows emacs-ag to be used on remote systems.

* gnu/packages/emacs.scm (emacs-ag)[inputs]: Remove.  Move THE-SILVER-SEARCHER
to...
[propagated-inputs]: ... here.
[arguments]: Remove 'patch-exec-paths' phase.

gnu: miniupnpc: Fix CVE-2017-8798.

* gnu/packages/patches/miniupnpc-CVE-2017-8798.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.
* gnu/packages/upnp.scm (miniupnpc)[source]: Use it.

gnu: cryptsetup-static: Fix FTBFS with lvm2-static@2.02.171.

* gnu/packages/cryptsetup.scm (cryptsetup-static)[arguments]<#:configure-flags>:
Add "-lm" to LIBS.

nls: Update 'fr' translation.

gnu: lxde-common: Provide 'startlxde' with the 'lxsession' file name.

Fixes <https://bugs.gnu.org/26688>.

* gnu/packages/lxde.scm (lxde-common)[arguments, inputs]: New fields.

gnu: Add antlr3 and stringtemplate4.

* gnu/packages/java.scm (antlr3, stringtemplate4): New variables.

gnu: Add stringtemplate3.

* gnu/packages/java.scm (stringtemplate3): New variable.

gnu: Add antlr2.

* gnu/packages/java.scm (antlr2): New variable.