ui: Make '--version' output GCS-compliant.

* guix/ui.scm (show-version-and-exit): Display copyright year, license,
  and LACK OF WARRANTY.

guix package: Show the output name of what's being removed.

* guix/scripts/package.scm (show-what-to-remove/install): Show the
  output name of packages being removed.

guix package: Fix indentation of "will be removed" messages.

* guix/scripts/package.scm (show-what-to-remove/install): Remove extra
  indentation from the removal sentences.

guix package: Allow removal of a specific package output.

Fixes <http://bugs.gnu.org/15756>.

* guix/profiles.scm (<manifest-pattern>): New record type.
  (remove-manifest-entry): Remove.
  (entry-predicate, manifest-matching-entries): New procedures.
  (manifest-remove): Accept a list of <manifest-pattern>.
  (manifest-installed?): Replace 'name' parameter by 'pattern', a
  <manifest-pattern>.
* guix/scripts/package.scm (options->removable): Return a list of
  <manifest-pattern>.
  (guix-package)[process-action]: Use 'manifest-matching-entries' to
  compute the list of packages to remove.
* tests/profiles.scm: New file.
* Makefile.am (SCM_TESTS): Add it.

guix package: Separate '--remove' option processing.

* guix/scripts/package.scm (options->removable): New procedure.
  (guix-package)[process-actions]: Use it.  Rename 'remove*' to 'remove'
  and 'install*' to 'install'.

ui: Factorize package specification parsing.

* guix/ui.scm (package-specification->name+version+output): New
  procedure.
* guix/scripts/package.scm (specification->package+output): Use it.
* tests/ui.scm ("package-specification->name+version+output"): New test.

Add (guix profiles).

* guix/scripts/package.scm (show-what-to-remove/install): New procedure,
  moved from...
  (guix-package): ... here.
  (<manifest>, make-manifest, <manifest-entry>,
  profile-manifest, manifest->sexp, sexp->manifest, read-manifest,
  write-manifest, remove-manifest-entry, manifest-remove,
  manifest-installed?, manifest=?, profile-regexp, generation-numbers,
  previous-generation-number, profile-derivation, generation-number,
  generation-file-name, generation-time, lower-input): Move to...
* guix/profiles.scm: ... here.  New file.
* Makefile.am (MODULES): Add it.

union: Do not warn when identical files collide.

* guix/build/union.scm (file=?): New procedure.
  (union-build)[resolve-collision]: Do not warn when identical files
  collide.

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>.