tests: Add `guix hash' test.

* guix/scripts/hash.scm (guix-hash)[eof->null]: New procedure.
  Use it to convert the EOF object to the empty bytevector.
* tests/guix-hash.sh: New file.
* Makefile.am (SH_TESTS): Add it.

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'.

package: Store the output path of packages installed with `-e'.

* guix/scripts/package.scm (guix-package)[process-actions](package->tuple):
  Put the output path in the tuple, not the derivation path.
* tests/guix-package.sh: Add test.

package: Make sure the dependencies get built along with the manifest.

Before this, something like "guix package -i glibc" could fail because
glibc lists linux-libre-headers as a propagated input (which would be
added as a dependency in the manifest) but the linux-libre-headers
output could be unavailable, leading to an error like this:

  path `/nix/store/4v2bk8sx5cm166gks3fi3q7d9zchibnk-linux-libre-headers-3.3.8' is not valid

This patch adds such dependencies as inputs of the profile derivation.

* guix/scripts/package.scm (profile-derivation): Accept package objects
  in the `deps' field of an element of PACKAGES.  Convert them to their
  output path for BUILDER, and add them to the inputs of the
  `build-expression->derivation' call.
  (input->name+path): When INPUT doesn't contain a package object,
  return it as is.
  (guix-package)[process-actions](canonicalize-deps): Expect DEPS to
  contain package objects, and leave them as is.

refresh: Gracefully handle failure to download a tarball.

* guix/scripts/refresh.scm (guix-refresh): When updating a source file,
  gracefully handle the case where TARBALL is #f.
  Reported by Nikita Karetnikov <nikita@karetnikov.org>.

package: Use ~/.guix-profile as the default for --search-paths.

* guix/scripts/package.scm (search-path-environment-variables): Prefer
  %USER-ENVIRONMENT-DIRECTORY when it points to PROFILE.
  (display-search-paths): Use 3 spaces for indentation.

package: Display the output of packages to be installed/removed.

* guix/scripts/package.scm (guix-package)[show-what-to-remove/install]:
  Display the output name.

package: Preserve the installed package output when upgrading.

* guix/scripts/package.scm (guix-package)[find-package]: Add optional
  parameter `output'.  Use it.
  [process-actions]: When computing UPGRADE, pass OUTPUT to
  `find-package'.

package: Fix spacing in user messages.

* guix/scripts/package.scm (guix-package)[process-actions]: Fix spacing.

refresh: Change default to not update source files.

* guix/scripts/refresh.scm (%options): Change `--dry-run' to `--update'.
  (show-help): Adjust accordingly.
  (guix-refresh): Likewise.

Merge branch 'core-updates'

substitute-binary: Support decompression from non-file ports.

* guix/scripts/substitute-binary.scm (filtered-port): Move to utils.scm.
  (decompressed-port): Upon "none", return '() as the second value.
  (guix-substitute-binary): Expect `decompressed-port' to return a list
  of PIDs as its second value.
* guix/utils.scm (filtered-port): New procedure.  Add case for when
  INPUT is not `file-port?'.
* tests/utils.scm ("filtered-port, file", "filtered-port, non-file"):
  New tests.

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'.

ui: Add `args-fold*' and use it.

* guix/ui.scm (args-fold*): New procedure.
* guix/scripts/build.scm, guix/scripts/download.scm,
  guix/scripts/gc.scm, guix/scripts/hash.scm, guix/scripts/import.scm,
  guix/scripts/package.scm, guix/scripts/pull.scm,
  guix/scripts/refresh.scm: Use `args-fold*' instead of `args-fold'.

pull: Use `download-to-store'.

* guix/scripts/pull.scm (download-and-store): Remove.
  (unpack): Use `download-to-store' instead.

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

refresh: Add `--select'.

* guix/scripts/refresh.scm (%options): Add `--select'.
  (show-help): Likewise.  Augment initial help text.
  (guix-refresh)[core-package?]: New procedure.
  Use it when selecting packages.

web: Factorize `http-get' hackery.

This should fix `substitute-binary --query' on Guile 2.0.5.

* guix/web.scm: New file.
* Makefile.am (MODULES): Add it.
* po/POTFILES.in: Add it.
* guix/gnu-maintenance.scm (http-fetch): Remove.
  (%package-list-url): Turn into a URI.
  (official-gnu-packages): Add #:text? #t to `http-fetch' call.
* guix/scripts/substitute-binary.scm (fetch): Remove `http' case, and
  use `http-fetch' instead.

Add `guix refresh' and related auto-update tools.

* guix/gnu-maintenance.scm (ftp-server/directory)[quirks]: Add glib.
  (package-update-path, download-tarball, package-update,
  update-package-source): New procedures.
* guix/gnupg.scm, guix/scripts/refresh.scm: New files.
* Makefile.am (MODULES): Add them.
* guix/utils.scm (file-extension): New procedure.

Factorize `download-and-store'.

* guix/download.scm (download-to-store): New procedure.
* guix/scripts/download.scm (fetch-and-store): Remove.
  (guix-download): Use `download-to-store' instead.
* guix/ui.scm (call-with-temporary-output-file): Move to...
* guix/utils.scm (call-with-temporary-output-file): ... here.