gnu: qt-5: Allow the use of DT_RUNPATH for libQt5WebEngineCore.so.

* gnu/packages/patches/qt5-runpath.patch: New file.
* gnu-system.am (dist_patch_DATA): Add it.
* gnu/packages/qt.scm (qt)[source]: Use it.

gnu: miniupnpc: Allow executables to find libupnp.so.

* gnu/packages/upnp.scm (miniupnpc)[arguments]: Pass
  "LDFLAGS=-Wl,-rpath=...".

gnu: libtocc: Help the tests find libtocc.so.

* gnu/packages/search.scm (libtocc)[arguments] <check>: Pass
  -Wl,-rpath=../src/.libs for the tests.

gnu: libmicrohttpd: Update to 0.9.40.

* gnu/packages/gnunet.scm (libmicrohttpd): Update to 0.9.40.

gnu: Disable RUNPATH validation for packages that use $ORIGIN.

* gnu/packages/haskell.scm (ghc)[arguments]: Add #:validate-runpath?.
* gnu/packages/julia.scm (julia)[arguments]: Likewise.
* gnu/packages/java.scm (icedtea6)[arguments]: Likewise.

gnu: glib: Move html documentation to $doc/share/gtk-doc/html.

* gnu/packages/glib.scm (glib)[arguments]<#:configure-flags>:
  Pass "--with-html-dir=$doc/share/gtk-doc/html".

gnu: openldap: Update to 2.4.40.

* gnu/packages/openldap.scm (openldap): Update to 2.4.40.

gnu: python: Use 'version-major+minor' to compute PYTHONPATH.

Fixes a regression introduced in 08c0450.

* gnu/packages/python.scm (python)[native-search-paths]: Use
  'version-major+minor' to compute PYTHONPATH.

gnu: gst-libav: Add missing quotes in phase names passed to 'modify-phases'.

This should have been done in 1ca8ff285ba0f055fbaf314d8a23fadc25839135.

* gnu/packages/gstreamer.scm (gst-libav): Add missing quotes in phase names
  passed to 'modify-phases'.

gnu: libepoxy: Fix tests on arm.

* gnu/packages/gl.scm (libepoxy)[arguments]: When building for arm,
  patch test/dlwrap.c to fix the tests.

Merge branch 'master' into core-updates

gnu: p11-kit: Update to 0.23.1.

* gnu/packages/gnutls.scm (p11-kit): Update to 0.23.1.

gnu: net-tools: Adapt to linux-libre-headers-3.14.x.

* gnu/packages/linux.scm (net-tools): Remove the HAVE_HWSTRIP and HAVE_HWTR
  options from the configuration.

services: Add upower.

* gnu-system.am (GNU_SYSTEM_MODULES): Add gnu/services/upower.scm.
* gnu/services/upower.scm: New file, defining a upower service.
* doc/guix.texi (Various Services): Mention it.

Co-authored-by: Ludovic Courtès <ludo@gnu.org>

gnu: Add upower.

* gnu/packages/gnome.scm (upower): New variable.
* gnu/packages/patches/upower-builddir.patch: New patch.
* gnu-system.am (dist_patch_DATA): Add it.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

lint: Add a 'derivation' checker.

* guix/scripts/lint.scm (check-derivation): New procedure.
  (%checkers): Add 'derivation' checker.
* tests/lint.scm ("derivation: invalid arguments"): New test.

gnu: gnutls: Update to 3.4.0.

* gnu/packages/patches/gnutls-fix-duplicate-manpages.patch: New file.
* gnu-system.am (dist_patch_DATA): Add it.
* gnu/packages/gnutls.scm (gnutls)[source]: Update to 3.4.0.  Add patch.
  [arguments]: Pass --without-p11-kit to 'configure'.
  [propagated-inputs]: Use 'nettle' instead of 'nettle-2'.  Add 'libidn'.

gnu: gnutls: Add debug output.

* gnu/packages/gnutls.scm (gnutls)[outputs]: Add debug output.

gnu: nettle: Add debug output.

* gnu/packages/nettle.scm (nettle)[outputs]: Add debug output.

doc: Add example showing how to customize 'nscd-service'.

* doc/guix.texi (Name Service Switch): Add link to nss-mdns.  Add
  example show how to pass #:name-services to 'nscd-service'.
  (Base Services): Add link from 'nscd-service' to the above.
* gnu/services/base.scm (nscd-service): Update docstring accordingly.