* srfi/srfi-37.scm.in: New file, taken from Guile 2.0.9.
* m4/guix.m4: New macro.
* configure.ac: Use it.  Define Automake conditional `INSTALL_SRFI_37'.
* Makefile.am (nobase_nodist_guilemodule_DATA)[INSTALL_SRFI_37]: Add
  srfi/srfi-37.scm.
  (GOBJECTS)[INSTALL_SRFI_37]: Add srfi/srfi-37.go.
  (srfi/srfi-37.scm)[INSTALL_SRFI_37]: New target.
  (EXTRA_DIST): Add srfi/srfi-37.scm.in.

* m4/guix.m4 (GUIX_ASSERT_SUPPORTED_SYSTEM): New macro.
* configure.ac: Use it.

* m4/guix.m4 (GUIX_SYSTEM_TYPE): Find `sed'.  Fix sed pattern in the
  non-Linux case.

* m4/guix.m4 (GUIX_ASSERT_GUILE_FEATURES): New macro.
* configure.ac: Use it.

* m4/guix.m4 (GUIX_SYSTEM_TYPE): Print the system type.

* distro/packages/openssl.scm, m4/guix.m4, nix/sync-with-upstream:
  Update headers.

* configure.ac: Compute and substitute `guix_localstatedir'.
* m4/guix.m4: Substitute `guix_system'.
* guix/config.scm.in (%store-directory, %store-directory, %system): New
  variables.
* guix/store.scm (%nix-state-dir): Remove.
  (%default-socket-path): Use %STATE-DIRECTORY as the default.
  (%store-prefix): Use %STORE-DIRECTORY as the default.
* guix/utils.scm (%current-system): Default to %SYSTEM.

* configure.ac: Call `AC_USE_SYSTEM_EXTENSIONS', and
  `GUIX_SYSTEM_TYPE'.  Add `--with-store-dir' option, and substitute
  `storedir'.  Include `config-daemon.ac'.
* config-daemon.ac: New file.
* Makefile.am [BUILD_DAEMON]: Include `daemon.am'.
* daemon.am: New file.
* m4/guix.m4 (GUIX_SYSTEM_TYPE): New macro.

* nix/libutil/gcrypt-hash.cc, nix/libutil/gcrypt-hash.hh,
  nix/libutil/md5.h, nix/libutil/sha1.h, nix/libutil/sha256.h,
  nix/nix-daemon/guix-daemon.cc, nix/nix-daemon/shared.hh: New files.

* guix/utils.scm (sha256): Remove Coreutils- and libchop-based
  implementations.
* README: Update accordingly.

* m4/guix.m4: New file.
* configure.ac: Use `GUIX_ASSERT_LIBGCRYPT_USABLE'.  Set and substitute
  `LIBGCRYPT_PREFIX'.
* Makefile.am (AM_DISTCHECK_CONFIGURE_FLAGS): Pass
  `--with-libgcrypt-prefix=$(LIBGCRYPT_PREFIX)'.