ui: Move 'show-manifest-transaction' from (guix profiles).

* guix/profiles.scm: Do not use (guix ui) module.
  (right-arrow, manifest-show-transaction): Move and rename to...
* guix/ui.scm (right-arrow, show-manifest-transaction): ... here.
* tests/profiles.scm ("manifest-show-transaction"): Move to...
* tests/ui.scm ("show-manifest-transaction"): ... here.
  (guile-1.8.8, guile-2.0.9): New variables.
* emacs/guix-main.scm (process-package-actions): Rename
  'manifest-show-transaction' to 'show-manifest-transaction'.
* guix/scripts/package.scm (guix-package): Likewise.

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

ui: Recognize the same size units as Coreutils.

* guix/ui.scm (size->number): Add a bunch of large units.  Recognize
  one-letter unit names.  Change "KB" to "kB".
* tests/ui.scm ("size->number, 1T"): New test.
* doc/guix.texi (Invoking guix gc): Add cross-reference to "Block size"
  in the Coreutils manual.
  (Invoking guix system): Likewise.

Merge branch 'master' into core-updates

ui: Fix handling of periods by fill-paragraph.

Fixes <http://bugs.gnu.org/17468>.

* guix/ui.scm (fill-paragraph): Two spaces after period and no spaces before newline.
* tests/ui.scm: New test case.

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

Merge branch 'master' into core-updates

ui: Gracefully deal with zero-output derivations.

* guix/ui.scm (show-what-to-build)[built-or-substitutable?]: New
  procedure.  Check whether OUT is #f.
  Use it.
* tests/ui.scm ("show-what-to-build, zero outputs"): New test.

ui: Add 'size->number'.

* guix/scripts/gc.scm (size->number): Remove.
* guix/ui.scm (size->number): New procedure.
* tests/ui.scm ("size->number, bytes",
  "size->number, MiB", "size->number, GiB", "size->number, 1.2GiB",
  "size->number, invalid unit"): New tests.

Merge branch 'master' into core-updates

Conflicts:
	guix/packages.scm

ui: Factorize package specification parsing.

* guix/ui.scm (package-specification->name+version+output): New
  procedure.
* guix/scripts/package.scm (specification->package+output): Use it.
* tests/ui.scm ("package-specification->name+version+output"): New test.

Merge branch 'master' into core-updates

guix package: Add '--list-generations'.

* guix/scripts/package.scm: Import (srfi srfi-19).
  (generation-time, matching-generations): New functions.
  (show-help): Add '--list-generations'.
  (%options): Likewise.
  (guix-package)[process-query]: Add support for '--list-generations'.
* guix/ui.scm: Import (srfi srfi-19) and (ice-9 regex).
  (string->generations, string->duration): New functions.
* tests/guix-package.sh: Test '--list-generations'.
* tests/ui.scm: Import (srfi srfi-19).
  Test 'string->generations' and 'string->duration'.
* doc/guix.texi (Invoking guix-package): Document '--list-generations'.

guix-package: Report `--search' matches in recutils format.

* guix/ui.scm (fill-paragraph, string->recutils, package->recutils): New
  procedures.
* guix-package.in (guix-package)[process-query]: Use `package->recutils'
  to display package meta-data.
* tests/guix-package.sh: Adjust test.
* tests/ui.scm: New file.
* Makefile.am (TESTS): Add it.
* doc/guix.texi (Invoking guix-package): Adjust `--search'
  documentation, and give an example.