Merge branch 'master' into dbus-update

hydra: Add Graphviz and help2man as inputs to the Guix job set.

* build-aux/hydra/guix.scm (tarball-package): Add GRAPHVIZ and HELP2MAN
  to 'native-inputs' of GUIX.

hydra: Update demo OS to new service interface.

* build-aux/hydra/demo-os.scm: Import (gnu services dbus); remove
  arguments to 'dbus-service'.

Merge branch 'core-updates'

Use "normalized codesets" everywhere.

In other words, change "xx_YY.UTF-8" to "xx_YY.utf8".

* guix/profiles.scm (ca-certificate-bundle): Use "en_US.utf8" instead of
  "en_US.UTF-8".
* guix/packages.scm (patch-and-repack): Likewise.
* guix/build/gnu-build-system.scm (install-locale): Likewise.
* guix/build-system/gnu.scm (gnu-build, gnu-cross-build): Likewise.
* gnu/packages/python.scm (python-ipython): Likewise.
* gnu/packages/gawk.scm (gawk): Likewise.
* build-aux/hydra/demo-os.scm: Likewise.
* gnu/packages/guile.scm (guile-ncurses)[arguments]: Remove
  'change-locale' phase.

Merge branch 'core-updates'

hydra: Remove cross-builds from armhf-linux to mips64el-linux-gnuabi64.

* build-aux/hydra/gnu-system.scm (hydra-jobs)[cross-jobs]: Modify
  'from-32-to-64?' to include 'armhf-linux' in the set of 32-bit systems.

check-available-binaries: Use 'substitutable-paths'.

* build-aux/check-available-binaries.scm: Rewrite to use 'substitutable-paths'
  instead of 'substitution-oracle'.  The latter does more than we need, and it
  no longer check the substitutability of valid items, which is not what we
  want.  Use 'lset-difference' instead of iterating over the items.

gnu: gcc-5.1, gcc-toolchain-5.1, libstdc++-doc-5.1: Rename to *-5.

This reflects the new version numbering scheme for GCC 5 and up.
See <https://gcc.gnu.org/develop.html>.

* gnu/packages/gcc.scm (gcc-5.1): Rename to ...
  (gcc-5): ... this.
  (libstdc++-doc-5.1): Rename to ...
  (libstdc++-doc-5): ... this, and use gcc-5.
* gnu/packages/commencement.scm (gcc-toolchain-5.1): Rename to ...
  (gcc-toolchain-5): ... this, and use gcc-5.
* build-aux/hydra/gnu-system.scm (%core-packages): Use gcc-5.

build: Generate 'AUTHORS'.

* build-aux/generate-authors.scm: New file.
* Makefile.am (gen-AUTHORS): New target.
  (dist-hook, .PHONY): Add it.

Merge branch 'master' into core-updates

hydra: Fix the demo OS.

* build-aux/hydra/demo-os.scm: Don't try to import (gnu services dbus), which
  no longer exists.  Use 'use-service-modules' and 'use-package-modules'.  Use
  "en_US.UTF-8" as system locale.

list-packages: Move to guix-artwork repository.

In order to integrate the package list in the GuixSD website, the listing of
packages has been moved into the website implementation.

* build-aux/list-packages.scm: Remove file.
* Makefile.am (EXTRA_DIST): Adapt to it.

hydra: Remove GCC 4.7 from the core set, and add 4.9 and 5.1.

* build-aux/hydra/gnu-system.scm (%core-packages): Remove GCC-4.7.  Add
  GCC-4.9 and GCC-5.1.

Merge branch 'master' into core-updates

hydra: Support per-package absolute build timeouts.

* build-aux/hydra/gnu-system.scm (package->alist): Use the 'timeout' value in
  the package 'properties' alist, if present.

Merge branch 'master' into gtk-rebuild

Conflicts:
	gnu/packages/gtk.scm

ui: Deduplicate 'show-what-to-build*'.

* guix/ui.scm (show-what-to-build*): New procedure.
* guix/scripts/environment.scm (show-what-to-build*): Delete.
* guix/scripts/system.scm (show-what-to-build*): Likewise.
* build-aux/make-binary-tarball.scm (show-what-to-build*): Likewise.

hydra: Increase USB image size.

* build-aux/hydra/gnu-system.scm (qemu-jobs): Increase disk image size
  to 860 MiB, for x86_64.

build: check-final-inputs-self-contained uses %HYDRA-SUPPORTED-SYSTEMS.

* build-aux/check-final-inputs-self-contained.scm: Change
  '%supported-systems' to '%hydra-supported-systems'.