Merge branch 'master' into dbus-update

ui: Add 'make-regexp*'.

Fixes <http://bugs.gnu.org/21773>.
Reported by Jan Synáček <jan.synacek@gmail.com>.

* guix/ui.scm (make-regexp*): New procedure.
* guix/scripts/package.scm (options->installable, guix-package): Use it
  when processing user-provided regexps.

profiles: Add generation manipulation procedures.

* guix/scripts/package.scm (delete-generations): Use
  'delete-generation*' instead of 'delete-generation'.
  (guix-package)[process-actions]: Use 'roll-back*' instead of
  'roll-back' and 'switch-to-generation*' instead of
  'switch-to-generation'.
  (link-to-empty-profile, switch-to-generation,
  switch-to-previous-generation, roll-back, delete-generation): Move
  to...
* guix/profiles.scm: ... here.  Adjust to not print messages and to
  return values that can be used by user interfaces.
* guix/ui.scm (display-generation-change, roll-back*,
  switch-to-generation*, delete-generation*): New procedures.

ui: Add procedures to display a profile generation.

* guix/scripts/package.scm (guix-package)[process-query](list-generations):
  Move part of the body to 'delete-generation' and
  'display-profile-content'.
* guix/ui.scm (display-generation, display-profile-content): New
  procedures.

utils: Add 'readlink*'.

* guix/scripts/package.scm (readlink*): Move to...
* guix/utils.scm (readlink*): ... here.  New procedure.

ui: Add 'matching-generations'.

* guix/scripts/package.scm (matching-generations): Move to...
* guix/ui.scm (matching-generations): ... here.

Merge branch 'master' into core-updates

Add (guix scripts).

* guix/ui.scm: Add missing copyright lines.
  (args-fold*, environment-build-options, %default-argument-handler,
  parse-command-line): Move to ...
* guix/scripts.scm: ...here.  New file.
* guix/scripts/archive.scm: Use it.
* guix/scripts/build.scm: Likewise.
* guix/scripts/download.scm: Likewise.
* guix/scripts/edit.scm: Likewise.
* guix/scripts/environment.scm: Likewise.
* guix/scripts/gc.scm: Likewise.
* guix/scripts/graph.scm: Likewise.
* guix/scripts/hash.scm: Likewise.
* guix/scripts/import/cpan.scm: Likewise.
* guix/scripts/import/cran.scm: Likewise.
* guix/scripts/import/elpa.scm: Likewise.
* guix/scripts/import/gem.scm: Likewise.
* guix/scripts/import/gnu.scm: Likewise.
* guix/scripts/import/hackage.scm: Likewise.
* guix/scripts/import/nix.scm: Likewise.
* guix/scripts/import/pypi.scm: Likewise.
* guix/scripts/lint.scm: Likewise.
* guix/scripts/package.scm: Likewise.
* guix/scripts/publish.scm: Likewise.
* guix/scripts/pull.scm: Likewise.
* guix/scripts/refresh.scm: Likewise.
* guix/scripts/size.scm: Likewise.
* guix/scripts/system.scm: Likewise.
* tests/ui.scm (with-environment-variable, "parse-command-line",
  "parse-command-line and --no options"): Move to ...
* tests/scripts.scm: ...here.  New file.
* Makefile.am (MODULES): Add guix/scripts.scm.
  (SCM_TESTS): Add tests/scripts.scm.
* po/guix/POTFILES.in: Add guix/scripts.scm.

scripts: package: Add --install-from-file option.

* guix/scripts/package.scm (show-help): Add help text for --install-from-file
  option.
  (%options): Add --install-from-file option.
* tests/guix-package.sh: Test it.
* doc/guix.texi ("invoking guix package"): Document it.
* doc/package-hello.scm: New file.
* doc.am (EXTRA_DIST): Add it.

Merge branch 'master' into core-updates

ui: Add 'leave-on-EPIPE'.

* guix/scripts/package.scm (leave-on-EPIPE): Move to...
* guix/ui.scm (leave-on-EPIPE): ... here.

Merge branch 'master' into core-updates

Move 'specification->package+output' to (gnu packages).

* guix/scripts/package.scm (specification->package+output): Move to...
* gnu/packages.scm (specification->package+output): ... here
* guix/scripts/archive.scm (guix): Adjust accordingly.

Merge branch 'master' into core-updates

guix: Clean up --help messages.

* guix/scripts/import.scm (show-help): Add newline before a list of
  importers.
* guix/scripts/lint.scm (show-help): Split a long description line.
* guix/scripts/package.scm (show-help): Improve docstrings for --install
  and --remove options.
* guix/scripts/system.scm (show-help): Format actions the same way as
  guix commands and importers are formatted.

guix package: Fix typo in --help message.

* guix/scripts/package.scm (show-help): Align '--show' option properly.

emacs: Report about "search paths" after operation.

* guix/scripts/package.scm: Export 'display-search-paths'.
* emacs/guix-main.scm (process-package-actions): Use it.

guix package: --manifest DTRT when combined with --dry-run.

* guix/scripts/package.scm (guix-package)[process-actions]: Process 'manifest
  action regardless of whether 'dry-run? is set.  Adjust the message
  accordingly.
* tests/guix-package.sh: Add error-reporting test.

Merge branch 'master' into gtk-rebuild

Conflicts:
	gnu/packages/gtk.scm

guix package: Adjust --help message.

* guix/scripts/package.scm (show-help): Add KIND parameter for
  --search-paths as a followup to dbc31ab.