syscalls: Fix ABI mismatch for 'clone'.

Fixes <http://bugs.gnu.org/21694>.

* guix/build/syscalls.scm (clone): Change 'syscall' parameter types to
  LONG, UNSIGNED-LONG, or '*; make sure it has 6 parameters.  Adjust
  caller accordingly.

gnu: mutt: Update to 1.5.24.

* gnu/packages/patches/mutt-CVE-2014-9116.patch: Delete file.
* gnu/packages/mail.scm (mutt): Update to 1.5.24.
  [source]: Update and remove patch.
* gnu-system.am (dist_patch_DATA): Unregister removed patch.

gnu: Add bspwm.

* gnu/packages/wm.scm (bspwm): New variable.

Signed-off-by: Alex Kost <alezost@gmail.com>

gnu: Add sxhkd.

* gnu/packages/xdisorg.scm (sxhkd): New variable.

Signed-off-by: Alex Kost <alezost@gmail.com>

emacs: Add "View graph" actions to system graph commands.

* emacs/guix-command.el (guix-command-additional-execute-arguments,
  guix-command-special-executors): Add "View graph" actions for
  'dmd-graph' and 'extension-graph' commands.

emacs: Disambiguate "d" key in 'system' popup.

* emacs/guix-command.el (guix-command-improve-system-argument): Use "D"
  key for 'disk-image' action (leave "d" for 'dmd-graph').

emacs: init: Add "share/emacs/site-lisp" to 'load-path'.

Fixes a regression introduced in 7741139080a6b00aa4f1846fe7668859e91bec58.

Reported by Ludovic Courtès <ludo@gnu.org>.

Not all emacs packages have "...-autoloads.el" files, so there is a
chance that "~/.guix-profile/share/emacs/site-lisp" will not be added to
'load-path', so add it unconditionally.

* emacs/guix-init.el: Add guix emacs directory to 'load-path'.  Move
  requiring 'guix-emacs' to the top-level.

system: Define 'GST_PLUGIN_PATH' in /etc/profile.

* gnu/system.scm (operating-system-etc-service)[profile]: Add
  'GST_PLUGIN_PATH' definition.

doc: Regenerate 'guix graph' examples.

* doc/images/coreutils-bag-graph.dot, doc/images/coreutils-graph.dot:
  Regenerate from current packages.  This removes the weird dependency
  on 'sed'.

gnu: Add python-libarchive-c.

* gnu/packages/python.scm (python-libarchive-c, python2-libarchive-c):
  New variables.

gnu: Add python-tlsh.

* gnu/packages/python.scm (python-tlsh, python2-tlsh): New variable.

gnu: Add ruby-yard.

* gnu/packages/ruby.scm (ruby-yard): New variable.

gnu: Add ruby-rspec-2.

* gnu/packages/ruby.scm (ruby-rspec-2): New variable.

gnu: Add ruby-rspec-mocks-2.

* gnu/packages/ruby.scm (ruby-rspec-mocks-2): New variable.

gnu: Add ruby-rspec-expectations-2.

* gnu/packages/ruby.scm (ruby-rspec-expectations-2): New variable.

gnu: Add ruby-rspec-core-2.

* gnu/packages/ruby.scm (ruby-rspec-core-2): New variable.

gnu: python-scipy: Add phase to fix tests.

* gnu/packages/python.scm (python-scipy)[arguments]: Add build phase
  "fix-tests".

gnu: python-scipy: Add numpydoc to native-inputs.

* gnu/packages/python.scm (python-numpydoc)[native-inputs]: Add
  python-numpydoc.

services: Unmount user file systems after process termination.

* gnu/services/base.scm (user-unmount-service-type): Change label and
  dmd name to 'user-file-systems'.
  (user-processes-service-type)[requirement]: Add 'user-file-systems'.

guix system: Add 'dmd-graph' command.

* guix/scripts/system.scm (dmd-service-node-label,
  dmd-service-node-type, export-dmd-graph): New procedures.
  (show-help): Add 'dmd-graph'.
  (guix-system)[parse-sub-command]: Likewise.
  Honor it.
* doc/guix.texi (Invoking guix system): Document it.
  (dmd Services): Add an illustration and explanation.
* doc/images/dmd-graph.dot: New file.
* doc.am (DOT_FILES): Add it.