doc: Add a note about optional GnuTLS dependency.

* README (Requirements): add a note about 'guix download''s GnuTLS dependency.
* doc/guix.texi (Requirements): Likewise.

Co-authored-by: Ludovic Courtès <ludo@gnu.org>

doc: Mention optional dependency on Guile-JSON.

* README (Requirements): Add Guile-JSON.
* doc/guix.texi (Requirements): Likewise.

Merge branch 'master' into core-updates

doc: Update "Installing Guix from Guix".

* README: Make 'guix package' command line more readable.  Mention
  --localstatedir.

Merge branch 'master' into core-updates

Conflicts:
	gnu/packages/base.scm

doc: Replace /nix/store with /gnu/store in README.

    * README update anachronistic reference to /nix/store

doc: Mention 'gcc-toolchain' in README.

* README (Installing Guix from Guix): Use "gcc-toolchain" instead of
  "gcc,binutils,ld-wrapper,glibc".

Merge branch 'master' into core-updates

Conflicts:
	guix/packages.scm

doc: Improve "Installing Guix from Guix" section.

Reported by Mark H. Weaver <mhw@netris.org>.

* README (Installing Guix from Guix): Explicitly mention $PATH
  separately.  Mention $ACLOCAL_PATH, not $ACLOCAL.  Give the exact
  command to install the dependencies.  Remove mention of
  $GUIX_LD_WRAPPER_ALLOW_IMPURITIES, which is no longer needed.

doc: Improve build instructions in README and HACKING.

* README (Requirements): Remove Nixpkgs.  Remove mentions of building
  from Git.
  (Installation): Refer to the manual.
* HACKING: List requirements for when building from Git.
  Remove the `dot: Command not found' error.

doc: Mark 2.0.5 as being the minimum Guile version.

* doc/guix.texi (Requirements): Require Guile 2.0.5+.
* README: Ditto.

doc: Describe the build procedure in more detail.

* README (Requirements): Replace "autoreconf" by "bootstrap".
  (Installing Guix from Guix): Augment and update.

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

doc: Add note on installing Guix from Guix.

* README (Installing Guix from Guix): New section.
  Suggested by Alex Sassmannshausen <alex.sassmannshausen@gmail.com>.

Merge branch 'master' into core-updates

Conflicts:
	distro/packages/multiprecision.scm

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.

Merge branch 'nix-integration'

Conflicts:
	tests/guix-package.sh

doc: Add new dependencies in `README'.

* README (Hacking): Rename to...
  (Requirements): ... this.  Add the daemon's dependencies.

doc: Mention the pronunciation of "Guix".

* README: Mention pronunciation of "Guix".
* doc/guix.texi (Introduction): Likewise.

doc: Update `README'.

* README: Update introductory summary.  Point to Savannah instead of
  Gitorious.  Mention <bug-guix@gnu.org>.
  (Guix & Nix): New section.