guix package: Factorize generation file name computation.

* guix/scripts/package.scm (generation-file-name): New procedure.
  Change all occurrences of (format #f "~a-~a-link" profile number) to
  use it.

guix package: Specify inputs for each manifest entry.

* guix/scripts/package.scm (<manifest-entry>): Add 'inputs' field.
  (manifest=?, lower-input): New procedure.
  (profile-derivation)[builder]: Add #:log-port argument to
  'union-build'.
  [ensure-valid-input]: Remove.
  Add each entry's inputs to the input list.
  (options->installable): Return just the list of entries.
  [package->manifest-entry]: Set 'inputs' field.
  [canonicalize-deps]: Rename to...
  [deduplicate]: ... this.  Remove input fiddling.
  (guix-package)[process-actions]: Use 'manifest=?' to compare the new
  and old manifests.  Pass directly PROF-DRV to 'show-what-to-build'.
  Pass #:print-build-trace #f to 'set-build-options'.

union: Make the log port a parameter.

* guix/build/union.scm (union-build): Add 'log-port' keyword parameter;
  use it.

derivations: 'derivation-path->output-path' honors the 'output' parameter.

* guix/derivations.scm (derivation-path->output-path): Pass OUTPUT.
* tests/derivations.scm ("multiple-output derivation,
  derivation-path->output-path"): New test.

guix package: Always use the term "profile", not "user environment".

* guix/scripts/package.scm (%user-environment-directory): Rename to...
  (%user-profile-directory): ... this.  Update users accordingly.
  (profile-derivation): Use the term "profile" instead of "user
  environment", and use "profile" as the derivation name.

guix package: Introduce <manifest> and <manifest-entry> types.

* guix/scripts/package.scm (<manifest>, <manifest-entry>): New record
  types.
  (make-manifest, read-manifest, manifest->sexp, sexp->manifest,
  read-manifest, write-manifest, remove-manifest-entry, manifest-remove,
  manifest-installed?): New procedures.
  (profile-derivation): Take a manifest as the second parameter.  Use
  'manifest->sexp'.  Expect <manifest-entry> objects instead of
  "tuples".  Adjust callers accordingly.
  (search-path-environment-variables): Changes 'packages' parameter to
  'entries'.  Rename 'package-in-manifest->package' to
  'manifest-entry->package'; expect <manifest-entry> objects.
  (display-search-paths): Rename 'packages' to 'entries'.
  (options->installable): Change 'installed' to 'manifest'.  Have
  'canonicalize-deps' return name/path tuples instead of raw packages.
  Rename 'package->tuple' to 'package->manifest-entry'.  Use
  <manifest-entry> objects instead of tuples.
  (guix-package)[process-actions]: Likewise.  Rename 'packages' to
  'entries'.
  [process-query]: Use 'manifest-entries' instead of
  'manifest-packages'.

guix package: Better separate option processing.

* guix/scripts/package.scm (find-package): Rename to...
  (specification->package+output): ... this.  Rename 'name' parmameter
  to 'spec'.  Return a package and output name instead of a tuple.
  (options->installable): New procedure
  (guix-package)[process-actions]: Use it, and remove corresponding
  code.

guix package: Declutter the entry point.

* guix/scripts/package.scm (newest-available-packages,
  find-best-packages-by-name, find-package, upgradeable?): New
  procedures, moved from...
  (guix-package): ... here.

build-system/{cmake,perl}: Don't use (guix build gnu-build-system).

Previously references to '%standard-phases' in builder-side code would
refer to the wrong one.

* guix/build-system/cmake.scm (cmake-build): Remove (guix build
  gnu-build-system) from the default MODULES value.
* guix/build-system/perl.scm (perl-build): Likewise.

records: define-record-type*: Field bindings are bound with 'let*'.

* guix/records.scm (define-record-type*): Wrap field bindings in a
  'let*', not in a 'letrec*', which turned out to be pointlessly
  inconvenient.
* tests/records.scm: Adjust test names accordingly.

guix package: '--search' matches against package names.

* guix/scripts/package.scm (find-packages-by-description): Return
  packages whose name matches RX.

pull: Compile modules correctly regardless of the compilation order.

* guix/scripts/pull.scm (unpack)[builder]: Work around
  <http://bugs.gnu.org/15602>.

guix: Make cmake build system aware of usual paths.

*  guix/build/cmake-build-system.scm (configure): Set CMAKE_LIBRARY_PATH to
     LIBRARY_PATH and CMAKE_INCLUDE_PATH to CPATH.

pull: Simplify the builder.

* guix/scripts/pull.scm (unpack)[builder]: Use 'copy-recursively' and
  'copy-file' instead of 'file-system-fold'.

build-system/perl: Lazily resolve (gnu packages perl).

* guix/build-system/perl.scm (default-perl): New procedure.
  (perl-build): Use it.

pull: Add '--url' option.

* guix/scripts/pull.scm (%default-options): Add 'tarball-url' pair.
  (%options, show-help): Add '--url'.
  (guix-pull): Honor it.

download: Support 'file://' URLs.

* guix/download.scm (download-to-store): When URL has a 'file' scheme or
  no scheme, use 'add-to-store' directly.

guix: Add missing call to 'bindtextdomain'.

* scripts/guix.in (config-lookup): Add "localedir" entry.
  (run-guix-main): Add call to 'bindtextdomain'.
* guix/ui.scm (initialize-guix): Use %GETTEXT-DOMAIN instead of a
  literal.

gnu-maintenance: Adjust URL of package description file.

* guix/gnu-maintenance.scm (%package-description-url): Adjust to the
  new URL.

snix: Prefer descriptions from the Womb rather than from Nixpkgs.

* guix/snix.scm (snix-derivation->guix-package): Use
  'gnu-package-doc-description' as the description for GNU packages.