Make `define-record-type*' error messages more informative.

* guix/utils.scm (define-record-type*): In case of missing or extra
  field initializers, raise a descriptive `syntax-error'.

distro: libsigsegv: Use multiple outputs.

* distro/base.scm (libsigsegv)[outputs]: New field
  (gawk)[arguments]: Clear.
  [inputs]: Add the "lib" output of LIBSIGSEGV.

guix-build: Display multiple outputs when needed.

* guix-build.in (guix-build): Display multiple outputs when there's more
  than one.

derivation: Coalesce multiple occurrences of the same input.

* guix/derivations.scm (write-derivation)[coalesce-duplicate-inputs]:
  New procedure.
  Use it to process INPUTS.

* tests/derivations.scm ("user of multiple-output derivation"): New
  test.

build: Don't auto-compile tests.

* Makefile.am (TESTS_ENVIRONMENT): Add `--no-auto-compile'.

gnu-build-system: Fix "libdir" and "includedir" for multiple-output drvs.

* guix/build/gnu-build-system.scm (configure): Change `--libdir' and
  `--includedir' to LIBDIR + "/lib" and INCLUDEDIR + "/include",
  respectively.

Upgrade Nix worker protocol.

We were already relying on the new version in `set-build-options', so
this patch fixes that.

* guix/store.scm (%protocol-version): Increase.
  (open-connection)[reserve-space?]: New argument.  Pass it to the
  server when it's recent enough.

derivation: Move sorting code to `write-derivation'.

* guix/derivations.scm (write-derivation): Sorte OUTPUTS, INPUTS,
  SOURCES, and ENV-VARS alphabetically.
  (derivation-hash): Leave INPUTS, SOURCES, and OUTPUTS unsorted.
  (derivation)[env-vars-with-empty-outputs]: Leave ENV-VARS unsorted.

build: Use `AM_GNU_GETTEXT_VERSION'.

* configure.ac: Add `AM_GNU_GETTEXT_VERSION'.  Suggested by
  Antono Vasiljev.

Fix `derivation-hash' for outputs not sorted alphabetically.

* guix/derivations.scm (derivation-hash): Reorder OUTPUTS.
* tests/derivations.scm ("multiple-output derivation, non-alphabetic
  order"): New test.

Add `propagated-inputs' and `properties' to <package>.

* guix/packages.scm (<package>)[propagated-inputs, properties]: New
  fields.
  (package-derivation): Update `match' clause.

Update list of dependencies.

* README: Require libgcrypt or libchop.

build: Build (guix utils) first.

* Makefile.am (MODULES): Move `guix/utils.scm' first.

build: Capitalize the package name.

* configure.ac: Use "Guix", not "guix", as the package name.

Add `guix-build'.

* guix-build.in: New file.

* configure.ac: Emit `guix-build'.  Add `commands-exec'.
* Makefile.am (bin_SCRIPTS): New variable.
* po/POTFILES.in: Add `guix-build.in'.

Add `derivation-prerequisites' and `derivation-prerequisites-to-build'.

* guix/derivations.scm (derivation-prerequisites,
  derivation-prerequisites-to-build): New procedures.

* tests/derivations.scm ("build-expression->derivation and
  derivation-prerequisites", "build-expression->derivation and
  derivation-prerequisites-to-build"): New tests.

Add the `valid-path?' RPC.

* guix/store.scm (valid-path?): New procedure.

* tests/builders.scm ("http-fetch", "gnu-build"): Use it.
* tests/derivations.scm ("add-to-store, flat", "add-to-store,
  recursive", "derivation with no inputs", "build derivation with 1
  source", "build derivation with coreutils",
  "build-expression->derivation with expression returning #f"):
  Likewise.

Add missing `set-build-options' parameters.

* guix/store.scm (set-build-options)[build-cores, use-substitutes?]: New
  keyword parameters.
  [send]: Change to expect a type, and use `write-arg'.
  Send settings for BUILD-CORES and USE-SUBSTITUTES? when the server
  supports it.

Add (distro) with a package searching facility.

* Makefile.am (MODULES): Add `distro.scm'.

* distro.scm: New file.
* po/POTFILES.in: Add it.

* tests/packages.scm ("find-packages-by-name", "find-packages-by-name
  with version"): New tests.

Add a libgcrypt-based implementation of `sha256'.

* guix/utils.scm (sha256): Add a libgcrypt-based implementation using
  the FFI.