Merge branch 'core-updates'

gnu: ffmpeg: Drop old version 2.2.

* gnu/packages/video.scm (ffmpeg-2.2): Remove variable.
  (ffmpeg)[arguments]: Drop LDFLAGS environment variable needed only for
  older versions.

monads: Optimize 'sequence'.

* guix/monads.scm (sequence): Rewrite as a macro.  This yields a 10%
  improvement in wall-clock time for 'guix system build'.

gnu: gnome-vfs: Tolerate 'test-async-cancel' failures, take two.

* gnu/packages/gnome.scm (gnome-vfs)[arguments]: Remove 'XFAIL_TESTS' make
  flag, which caused 'make check' to fail if the test unexpectedly passed.
  Add 'patch-test-async-cancel-to-never-fail' phase.

Merge branch 'master' into core-updates

Conflicts:
	gnu-system.am
	gnu/packages/gstreamer.scm

services: Explicitly refer to Shadow when requiring the 'nologin' shell.

* gnu/services/avahi.scm (avahi-service): Change 'shell' to a gexp
  referring to "nologin" in the SHADOW package.
* gnu/services/dbus.scm (dbus-service): Likewise.
* gnu/services/networking.scm (ntp-service, tor-service): Likewise.

system: Populate /etc/shells with the list of all the shells in use.

Reported by Andy Wingo <wingo@pobox.com>.

* gnu/system.scm (user-shells, shells-file): New procedures.
  (etc-directory): Add #:shell parameter.  Use 'shells-file' instead of
  'text-file'.
  (operating-system-etc-directory): Call 'user-shells' and pass #:shells
  to 'etc-directory'.

gnu: Add libsrtp.

* gnu/packages/telephony.scm (libsrtp): New variable.

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

gnu: icecat: Use system sqlite.

* gnu/packages/gnuzilla.scm (icecat)[inputs]: Add sqlite.
  [arguments]: Pass "--enable-system-sqlite" to configure.

gnu: gnome-vfs: Expect 'test-async-cancel' failure, and clean up.

* gnu/packages/gnome.scm (gnome-vfs)[arguments]: Add
  "XFAIL_TESTS=test-async-cancel" to make flags.  Remove ignored and
  undocumented 'DISABLE_DEPRECATED_CFLAGS' configure flag.  Simplify
  'ignore-deprecations' phase and return #t.  Reformat to fit within
  80 columns.

gnu: linux-libre: Set CONFIG_DEVMEM=y

* gnu/packages/linux.scm (linux-libre): Set CONFIG_DEVMEM=y.

Signed-off-by: Jason Self <j@jxself.org>

refresh: Allow users to refer to specific package versions.

* guix/scripts/refresh.scm (guix-refresh): Use 'specification->package'
  instead of 'find-packages-by-name'.  This allows users to specify
  things like "qt-4.8.6".
* doc/guix.texi (Invoking guix refresh): Add an example.

gnu: Add second ld-wrapper to work around readlink dereferencing bug.

Suggested by Mark H Weaver.

* gnu/packages/ld-wrapper2.in: New file.
* gnu-system.am (MISC_DISTRO_FILES): Add it.
* gnu/packages/commencement.scm (fixed-ld-wrapper): New procedure.

gnu: bigloo: Add RUNPATH to the libraries.

* gnu/packages/scheme.scm (bigloo)[arguments]: Pass --ldflags
  'configure' flag.

gnu: mig: Update to 1.5

* gnu/packages/hurd.scm (mig): Update to version 1.5.

gnu: hurd-headers: Update to 0.6

* gnu/packages/hurd.scm (hurd-headers): Update to version 0.6.

gnu: gnumach-headers: Update to 1.5

* gnu/packages/hurd.scm (gnumach-headers): Update to version 1.5.

gnu: vlc: Update to 2.2.0.

* gnu/packages/video.scm (vlc): Update to 2.2.0.
  [inputs]: Switch from ffmpeg-2.2 to latest one.

gnu: ffmpeg: Allow tests to run from the build tree.

* gnu/packages/video.scm (ffmpeg)[arguments]: Add 'set-ld-library-path'
  phase.

gnu: ffmpeg: Use 'modify-phases'.

* gnu/packages/video.scm (ffmpeg)[arguments]: Use 'modify-phases'
  instead of 'alist-cons-after' et al.