build: Avoid brace expansion in `nix/sync-with-upstream'.

* nix/sync-with-upstream: Avoid brace expansion, for the sake of Dash.

daemon: Build `nix-setuid-helper'.

* daemon.am (libexec_PROGRAMS, nix_setuid_helper_SOURCES,
  nix_setuid_helper_CPPFLAGS, nix_setuid_helper_LDADD): New variables.
* test-env.in: Set and export `NIX_SETUID_HELPER'.
* README (Installing Guix as non-root): New section.

download: Work around (web client) bug <http://bugs.gnu.org/13095>.

* guix/build/download.scm: Annihilate `shutdown' in (web client).

release.nix: Remove trailing "/nix" from localstatedir.

* release.nix (tarball, build): Use /nix/var as localstatedir, as a
  follow-up to 7f4f065.

build: Fix default value of `%state-directory'.

* guix/config.scm.in (%state-directory): Append `/nix'.
  Reported by Andreas Enge <andreas@enge.fr>.

build: Have `bootstrap' run all the necessary steps.

* bootstrap: Always run "git submodule init".  Run
  `nix/sync-with-upstream'.
  Reported by Nikita Karetnikov and Andreas Enge.

guix-package: Avoid use of the `guix' sub-directory for profiles.

* guix-package.in (%current-profile): Change to `guix-profile'.

release.nix: tarball: Fix typo.

* release.nix (tarball): Replace "gnulib" by "nix".

guix-package: Use directory names from (guix config).

* guix-package.in (%profile-directory): Use %STATE-DIRECTORY instead of
  a hard-coded directory.

distro: lout: Comment out dependency on Ghostscript.

* distro/packages/lout.scm (lout): Temporarily comment out dependency on
  Ghostscript as this was causing evaluation errors on Hydra.

Merge branch 'nix-integration'

Conflicts:
	tests/guix-package.sh

release.nix: Add `build_disable_daemon'.

* release.nix (build_disable_daemon): New job.

release.nix: build: Allow builds within a chroot.

* release.nix (build): Remove `__noChroot' and `preConfigure'.

tests: Skip network-dependent tests when the network is unreachable.

* tests/builders.scm (network-reachable?): New variable.
  ("url-fetch", "gnu-build"): Skip unless NETWORK-REACHABLE?.
* tests/derivations.scm (%coreutils): Check for network access.
  ("build-expression->derivation with one input"): Skip when %COREUTILS
  is #f.
* tests/guix-package.sh: Skip installation of GNU Make when the network
  is unreachable.
* tests/packages.scm ("GNU Make, bootstrap"): Likewise.
* tests/union.scm ("union-build"): Likewise.

release.nix: Build the daemon.

* release.nix (tarball): Add `preAutoconf'.  Augment `buildInputs' and
  `configureFlags' to allow daemon builds.
  (build): Likewise.

build: Make `--enable-daemon' the default.

* configure.ac: Have $guix_build_daemon default to "yes".

build: When `--enable-daemon', don't error out when Nix programs are missing.

* config-daemon.ac: Move AC_ARG_ENABLE([daemon]...)...
* configure.ac: ... here.
  When Nix programs are not found, error out only when
  $guix_build_daemon is no.

tests: Arrange to have the socket file name fit in `sun_path'.

* test-env.in (NIX_STATE_DIR): Choose a slightly smaller directory name.

tests: base32: Work around `system*' bug.

* tests/base32.scm (%nix-hash): When `getenv' returns the empty string,
  ignore it.
  (%have-nix-hash?): New variable.  Update `test-skip' clause to use it.

daemon: Use `openssl' from $PATH.

* daemon.am (-DOPENSSL_PATH): Default to "openssl".
* TODO: Mention removal of OpenSSL dependency.