syscalls: Add 'mount-points'.

* guix/build/syscalls.scm (mount-points): New procedure.
* tests/syscalls.scm ("mount-points"): New test.

install: Add GRUB to the set of global packages.

* gnu/system/install.scm (installation-os)[packages]: Add GRUB.

nls: Add a few more package modules for translation.

* po/packages/POTFILES.in: List a few more files.

licenses: Add 'silofl1.1'.

* guix/licenses.scm (silofl1.1): New variable.

doc: Mention 'guix environment' in "Features"; add index entries.

* doc/guix.texi (Features): Add paragraph about 'guix environment'.
  (Build Systems): Add @cindex.
  (Invoking guix environment): Ditto.

Update NEWS.

Thank Philip Woods.

doc: Add "GRUB Configuration".

* doc/guix.texi (operating-system Reference): Add xref to "GRUB
  Configuration".
  (GRUB Configuration): New node.

doc: Avoid @indentedblock, which is not supported by Texinfo 4.

Reported by Mark H Weaver.

* doc/guix.texi (Security Updates): Use @quotation instead of
  @indentedblock; the latter is not supported by Texinfo 4.

emacs: Improve 'guix-redisplay-buffer'.

* emacs/guix-base.el (guix-redisplay-buffer): Allow to display new entries.
  Restore point position.

emacs: Add 'guix-find-file'.

* emacs/guix-utils.el (guix-find-file): New procedure.
* emacs/guix-info.el (guix-file): Use it.

emacs: Restore mode-line after operation prompt.

* emacs/guix-base.el (guix-operation-prompt): Restore 'mode-line-format' after
  prompting.

emacs: Add "c" key binding to copy a button link.

* emacs/guix-info.el (guix-info-button-map): New variable.
  (guix-info-button-copy-label): New procedure.
* doc/emacs.texi (Emacs Info buffer): Mention a "c" key binding.
  (Emacs Keymaps): Add 'guix-info-button-map'.

gnu: Add polkit-qt.

* gnu/packages/polkit.scm (polkit-qt): New variable.

gnu: Add guile-sdl.

* gnu/packages/sdl.scm (guile-sdl): New variable.

gnu: Add sdl-union.

* gnu/packages/sdl.scm (sdl-union): New variable.

pull: Use the build procedure provided by the newly-downloaded Guix.

Fixes <http://bugs.gnu.org/18534>.

* guix/scripts/pull.scm (with-environment-variable, with-PATH): New
  macros.
  (temporary-directory, first-directory, interned-then-deleted): New
  procedures.
  (unpack): Rewrite to do the unpacking in the current process rather
  than as a separate derivation.
  (%self-build-file): New variable.
  (build-from-source): New procedure.
  (build-and-install): Use it.
* guix/build/pull.scm (build-guix): Rename 'tarball' argument to
  'source'.  Remove #:tar and #:gzip parameters, as well as 'tar'
  invocation.  Remove 'scandir' invocation.  Wrap body in
  'with-directory-excursion'.
* build-aux/build-self.scm: New file.
* Makefile.am (EXTRA_DIST): Add it.

gexp: Add #:module-path parameter to 'gexp->derivation'.

* guix/gexp.scm (gexp->derivation): Add #:module-path parameter, and
  pass it to 'imported-modules' and 'compiled-modules'.
* doc/guix.texi (G-Expressions): Adjust accordingly.

gnu: Re-synchronize a couple of synopses with the Womb.

* gnu/packages/lisp.scm (gcl): Synchronize synopsis.
* gnu/packages/scheme.scm (mit-scheme): Ditto.

gnu: Add polkit.

* gnu/packages/polkit.scm (polkit): New variable.
* gnu/packages/patches/polkit-drop-test.patch: New file.
* gnu-system.am (dist_patch_DATA): Register patch file.