gnu: perl-www-opensearch: Provide Module::Install.

* gnu/packages/web.scm (perl-www-opensearch)[native-inputs]: Add PERL-MODULE-INSTALL.

gnu: perl-xml-atom: Update to 0.42.

* gnu/packages/xml.scm (perl-xml-atom): Update to 0.42.
[arguments]: Add 'set-perl-search-path' phase.
[native-inputs]: Add PERL-HTML-TAGSET and PERL-MODULE-BUILD-TINY.

gnu: babl: Update to 0.1.30.

* gnu/packages/gimp.scm (babl): Update to 0.1.30.

gnu: Remove unneeded import.

* gnu/packages/engineering.scm: Don't import (srfi srfi-1) in top scope.

gnu: tdb: Update to 1.3.15.

* gnu/packages/databases.scm (tdb): Update to 1.3.15.

gnu: enlightenment: Update to 0.21.9.

* gnu/packages/enlightenment.scm (enlightenment): Update to 0.21.9.

gnu: xauth: Enable tests.

* gnu/packages/xorg.scm (xauth)[arguments]: Enable tests.
[native-inputs]: Add cmdtest.

gnu: Add cmdtest.

* gnu/packages/check.scm (cmdtest): New variable.

Co-authored-by: Arun Isaac <arunisaac@systemreboot.net>

Merge branch 'core-updates'

gnu: gnome: Depend on xdg-user-dirs.

* gnu/packages/gnome.scm (gnome): Add xdg-user-dirs dependency.  The presence
  of the autostart file in /run/current-system/profile/etc/xdg should cause
  xdg-user-dirs to be run when a user logs in, ensuring that they have
  ~/Pictures and other well-known user directories.

gnu: Add xdg-user-dirs.

* gnu/packages/freedesktop.scm (xdg-user-dirs): New public variable.

gnu: Add radare2.

* gnu/packages/engineering.scm (radare2): New variable.

gnu: Add python-capstone.

* gnu/packages/engineering.scm (python-capstone, python2-capstone): New
variables.

gnu: Add capstone.

* gnu/packages/engineering.scm (capstone): New variable.

gnu: youtube-dl: Update to 2017.08.23.

* gnu/packages/video.scm (youtube-dl): Update to 2017.08.23.

Signed-off-by: Arun Isaac <arunisaac@systemreboot.net>

gnu: pv: Update to 1.6.6.

* gnu/packages/pv.scm (pv): Update to 1.6.6.

gnu: linux-libre: Update to 4.12.9.

* gnu/packages/linux.scm (%linux-libre-version): Update to 4.12.9.
(%linux-libre-hash): Update hash.

gnu: linux-libre@4.9: Update to 4.9.45.

* gnu/packages/linux.scm (linux-libre-4.9): Update to 4.9.45.

gnu: linux-libre@4.4: Update to 4.4.84.

* gnu/packages/linux.scm (linux-libre-4.4): Update to 4.4.84.

gnu: perl: Add more missing dependencies on Module::Install.

* gnu/packages/databases.scm (perl-dbix-class, perl-dbix-class-cursor-cached,
  perl-dbix-class-introspectablem2m,
  perl-dbix-class-schema-loader)[native-inputs]: Add PERL-MODULE-INSTALL.
* gnu/packages/web.scm (perl-catalyst-action-renderview,
  perl-catalyst-action-rest, perl-catalyst-authentication-store-dbix-class,
  perl-catalyst-component-instancepercontext, perl-catalyst-model-dbic-schema,
  perl-catalyst-plugin-authentication,
  perl-catalyst-plugin-authorization-roles, perl-catalyst-plugin-configloader,
  perl-catalyst-plugin-session, perl-catalyst-plugin-session-state-cookie,
  perl-catalyst-plugin-stacktrace, perl-catalyst-plugin-static-simple,
  perl-catalyst-traitfor-request-proxybase, perl-catalyst-view-download,
  perl-catalyst-view-json, perl-catalystx-script-server-starman,
  perl-test-www-mechanize, perl-test-www-mechanize-catalyst)[native-inputs]:
  Likewise.
* gnu/packages/xorg.scm (perl-x11-xcb)[native-inputs]: Likewise.