Merge branch 'master' into core-updates

Conflicts:
	gnu/packages/make-bootstrap.scm

guix gc: Add `--requisites'.

* guix/scripts/gc.scm (show-help, %options): Add `--requisites'.
  (guix-gc): Handle it.
* doc/guix.texi (Invoking guix gc): Document `--requisites'.
* NEWS: Update.

doc: Write about patch submission and packaging guidelines.

* HACKING: Update the command names from `guix-build' to `guix build' & co.
  (Submitting Patches, Packaging Guidelines): New sections.
* doc/guix.texi (Contributing): New section.

build, package: Add `--fallback' option.

* guix/scripts/build.scm (%options, show-help): Add `--fallback'.
  (guix-build): Call `set-build-options' with #:fallback?.
* guix/scripts/package.scm (%options, show-help): Add `--fallback'.
  (guix-package): Call `set-build-options' with #:fallback?.
* doc/guix.texi (Invoking guix package, Invoking guix build): Document
  `--fallback'.

doc: Improve wording and fix typos in "Introduction" and "Requirements".

* doc/guix.texi (Introduction, Requirements): Rephrase and fix typos.

build: Add `--target' option.

* guix/scripts/build.scm (derivations-from-package-expressions): Add
  `package-derivation' parameter.
  (show-help, %options): Add `--target'.
  (guix-build): Use `package-cross-derivation' when `--target' is
  passed.
* tests/guix-build.sh: Add dry-run test with `--target'.
* doc/guix.texi (Invoking guix build): Document `--target'.

packages: Implement `package-cross-derivation'.

* guix/packages.scm (package-transitive-target-inputs,
  package-transitive-native-inputs): New procedures.
  (package-derivation): Parametrize `%current-target-system'.
  (package-cross-derivation): Implement.
* guix/utils.scm (%current-target-system): New variable.
* tests/packages.scm ("package-cross-derivation"): New test.
* doc/guix.texi (Defining Packages): Document
  `package-cross-derivation'.

Add `--max-silent-time' to `guix build' and `guix package'.

* guix/scripts/build.scm (%default-options): Add default
  `max-silent-time' value.
  (show-help, %options):  Add `--max-silent-time'.
  (guix-build): Pass `max-silent-time' to `set-build-options'.
* guix/scripts/package.scm (%default-options): Add default
  `max-silent-time' value.
  (show-help, %options):  Add `--max-silent-time'.
  (guix-package): Pass `max-silent-time' to `set-build-options'.
* guix/ui.scm (string->number*): New procedure.
* tests/derivations.scm ("build-expression->derivation and
  max-silent-time"): New test.
* doc/guix.texi (Invoking guix package, Invoking guix build): Document
  `--max-silent-time'.

package: Make sure the profile directory is owned by the user.

* guix/scripts/package.scm (guix-package)[ensure-default-profile]: Check
  the owner of %PROFILE-DIRECTORY.  Report an error when the owner is
  not the current user.  Add `rtfm' procedure.
* doc/guix.texi (Invoking guix package): Mention the ownership test.

doc: Document "guix download".

* doc/guix.texi (Defining Packages): Linke to "Invoking guix download".
  (Utilities): Add an overview paragraph.
  (Invoking guix download): New node.

refresh: Add `--key-server' and `--gpg'.

* guix/scripts/refresh.scm (%options): Add `--key-server' and `--gpg'.
  (show-help): Update accordingly.
  (update-package): New procedure, formerly in `guix-refresh'.
  (guix-refresh): Use it.  Parameterize `%openpgp-key-server' and
  `%gpg-command'.

doc: Document `guix refresh'.

* doc/guix.texi (Defining Packages): Add cross-reference to "Invoking
  guix refresh".
  (Invoking guix refresh): New node.

Merge branch 'core-updates'

guix package: Add `--search-paths' & co.

* guix/scripts/package.scm (search-path-environment-variables,
  display-search-paths): New procedures.
  (show-help, %options): Add `--search-paths'.
  (guix-package)[process-actions]: Call `display-search-paths' once the
  profile is ready.
  [process-query]: Honor `search-paths'.

Merge branch 'master' into core-updates

Conflicts:
	Makefile.am
	gnu/packages/autotools.scm
	gnu/packages/guile.scm
	gnu/packages/python.scm
	gnu/packages/shishi.scm
	guix/gnu-maintenance.scm
	guix/scripts/build.scm
	guix/scripts/gc.scm
	guix/scripts/package.scm
	guix/scripts/substitute-binary.scm
	guix/ui.scm
	nix/nix-daemon/guix-daemon.cc
	test-env.in
	tests/nar.scm
	tests/store.scm

Add 'guix hash'.

* guix/scripts/hash.scm: New file.
* Makefile.am (MODULES): Add it.
* po/POTFILES.in: Add it.
* doc/guix.texi (Invoking guix hash): New node.
  (Defining Packages): Add a cross-reference to the 'Invoking guix
  hash' node.

daemon: Add `--no-substitutes'.

Suggested by Mark H. Weaver.

* nix/nix-daemon/guix-daemon.cc (GUIX_OPT_NO_SUBSTITUTES): New macro.
  (options): Add `--no-substitutes'.
  (parse_opt): Add `GUIX_OPT_NO_SUBSTITUTES' case.
  (main): Leave `settings.substituters' empty when
  `settings.useSubstitutes' is false.

doc: Mention the home page.

* doc/guix.texi (Installation): Add a sentence pointing to the home
  page.  Suggested by Arne Babenhauserheide.

doc: Transparent binary deployment is implemented.

* doc/guix.texi (Features): Remove footnote saying that transparent
  binary deployment is not implemented.

package: allow users to upgrade the whole system by not providing a regexp.

* guix/scripts/packages.scm (guix-package) [process-actions]: When upgrading,
use "" when REGEXP is #f.
* doc/guix.texi: update the documentation accordingly.