gnu: pkg-config: Export package definition.

* gnu/packages/pkg-config.scm (%pkg-config): Make public.
  Reported by Andreas Enge <andreas@enge.fr>.

gnu: pkg-config: Provide a cross-build-friendly wrapper.

* gnu/packages/pkg-config.scm (pkg-config): Rename to...
  (%pkg-config): ... this.  Make private.
  (cross-pkg-config, pkg-config-for-target): New procedures.
  (pkg-config): New macro.

Merge branch 'core-updates'

packages: Add `native-search-paths' field and honor it.

* guix/packages.scm (<search-path-specification>): New record type.
  (search-path-specification->sexp): New procedure.
  (<package>)[native-search-paths]: New field.
  (package-derivation): Accumulate the search paths, and pass them
  as #:search-paths toe BUILDER.
* guix/build-system/gnu.scm (gnu-build): Add #:search-paths.  Compute
  `implicit-search-paths'.  Pass #:search-paths in BUILDER.
* guix/build-system/perl.scm (perl-build): Add #:search-paths, pass it
  to BUILDER with the search paths of PERL.
* guix/build-system/cmake.scm (cmake-build): Add #:search-paths, pass it
  to BUILDER.
* guix/build-system/trivial.scm (trivial-build): Add #:search-paths,
  ignore it.
* guix/build/gnu-build-system.scm (set-paths): Add #:search-paths.
  Remove explicit settings of CPATH, LIBRARY_PATH, and PKG_CONFIG_PATH.
  Instead, walk SEARCH-PATHS and call `set-path-environment-variable'
  for them.
* guix/build/perl-build-system.scm (perl-build): Remove PERL5LIB setting.
* tests/packages.scm ("search paths"): New test.
* gnu/packages/bootstrap.scm (%bootstrap-guile)[raw]: Add
  #:search-paths.
  (%bootstrap-gcc): Add `native-search-paths' field.
* gnu/packages/perl.scm (perl): Likewise.
* gnu/packages/pkg-config.scm (pkg-config): Likewise.
* gnu/packages/glib.scm (intltool): Remove `arguments'.
* gnu/packages/avahi.scm (avahi): Remove #:phases.

Re-export `%current-system' from (guix packages).

* guix/packages.scm: Re-export `%current-system'.
* gnu/packages/bdw-gc.scm, gnu/packages/gawk.scm,
  gnu/packages/gperf.scm, gnu/packages/libffi.scm,
  gnu/packages/libsigsegv.scm, gnu/packages/libunistring.scm,
  gnu/packages/lout.scm, gnu/packages/m4.scm,
  gnu/packages/multiprecision.scm, gnu/packages/ncurses.scm,
  gnu/packages/perl.scm, gnu/packages/pkg-config.scm,
  gnu/packages/readline.scm, gnu/packages/recutils.scm,
  gnu/packages/scheme.scm: Remove (guix utils) import.

distro: Change the module name space to (gnu ...).

* distro: Rename to...
* gnu: ... this.  Update module names accordingly.
* Makefile.am: Adjust accordingly.
* po/POTFILES.in: Likewise.
* distro.scm: Search for files under /gnu/packages instead of
  /distro/packages.
* gnu/packages/base.scm (ld-wrapper-boot3): Likewise.

Merge branch 'master' into core-updates

Conflicts:
	build-aux/download.scm
	distro/packages/autotools.scm
	distro/packages/base.scm
	distro/packages/bootstrap.scm
	distro/packages/lsh.scm
	distro/packages/make-bootstrap.scm
	distro/packages/ncurses.scm
	distro/packages/perl.scm
	tests/derivations.scm
	tests/union.scm

Update license headers.

Change all license headers, except guix/build/* and ld-wrapper.scm, with
this code:

  (use-modules (guix build utils)
	       (srfi srfi-1))

  (fluid-set! %default-port-encoding "UTF-8")

  (substitute* (remove (lambda (f)
			 (or (string-contains f ".tar.")
			     (string-contains f ".git/")
			     (string-contains f ".so")
			     (string-suffix? ".o" f)
			     (string-suffix? ".a" f)
			     (string-suffix? ".go" f)
			     (string-suffix? ".pdf" f)
			     (string-suffix? ".png" f)
			     (string-suffix? ".info" f)
			     (equal? (basename f) "guix-daemon")
			     (equal? (basename f) "nix-setuid-helper")
			     (string-contains f "nix-upstream/")
			     (string-contains f "distro/packages/bootstrap/")))
		       (find-files "." "\\.[a-z]+$"))
    (("^([[:graph:]]+) This file is part of Guix." _ comment-start)
     (string-append comment-start " This file is part of GNU Guix."))
    (("^([[:graph:]]+) Guix --- Nix package management.*" _ comment-start)
     (string-append comment-start
		    " GNU Guix --- Functional package management for GNU\n"))
    (("^([[:graph:]]+) Guix is " _ comment-start)
     (string-append comment-start " GNU Guix is "))
    (("^([[:graph:]]+) along with Guix." _ comment-start)
     (string-append comment-start " along with GNU Guix."))
    (("^([[:graph:]]+) Copyright \\(C\\)" _ comment-start)
     (string-append comment-start " Copyright ©")))

Change headers using C-style comments manually.

Merge branch 'master' into core-updates

Conflicts:
	distro/packages/multiprecision.scm

distro: Use (guix licenses) instead of strings.

* distro/packages/acl.scm, distro/packages/attr.scm,
  distro/packages/autotools.scm, distro/packages/base.scm,
  distro/packages/bash.scm, distro/packages/bdw-gc.scm,
  distro/packages/bison.scm, distro/packages/bootstrap.scm,
  distro/packages/compression.scm, distro/packages/cpio.scm,
  distro/packages/ddrescue.scm, distro/packages/ed.scm,
  distro/packages/flex.scm, distro/packages/gawk.scm,
  distro/packages/gdbm.scm, distro/packages/gettext.scm,
  distro/packages/gnupg.scm, distro/packages/gnutls.scm,
  distro/packages/gperf.scm, distro/packages/guile.scm,
  distro/packages/help2man.scm, distro/packages/less.scm,
  distro/packages/libffi.scm, distro/packages/libsigsegv.scm,
  distro/packages/libunistring.scm, distro/packages/linux.scm,
  distro/packages/lout.scm, distro/packages/lsh.scm,
  distro/packages/m4.scm, distro/packages/multiprecision.scm,
  distro/packages/nano.scm, distro/packages/ncurses.scm,
  distro/packages/nettle.scm, distro/packages/perl.scm,
  distro/packages/pkg-config.scm, distro/packages/pth.scm,
  distro/packages/readline.scm, distro/packages/recutils.scm,
  distro/packages/shishi.scm, distro/packages/system.scm,
  distro/packages/texinfo.scm, distro/packages/time.scm,
  distro/packages/wget.scm, distro/packages/which.scm,
  distro/packages/zile.scm: Use (guix licenses).

Remove (guix http) and (guix ftp).

* guix/ftp.scm, guix/http.scm, guix/build/ftp.scm, guix/build/http.scm:
  Remove.
* Makefile.am (MODULES): Likewise.
* tests/builders.scm, distro/packages/base.scm,
  distro/packages/bash.scm, distro/packages/bdw-gc.scm,
  distro/packages/compression.scm, distro/packages/gawk.scm,
  distro/packages/gnupg.scm, distro/packages/gperf.scm,
  distro/packages/guile.scm, distro/packages/libffi.scm,
  distro/packages/libsigsegv.scm, distro/packages/libtool.scm,
  distro/packages/libunistring.scm, distro/packages/lout.scm,
  distro/packages/m4.scm, distro/packages/multiprecision.scm,
  distro/packages/ncurses.scm, distro/packages/perl.scm,
  distro/packages/pkg-config.scm, distro/packages/pth.scm,
  distro/packages/readline.scm, distro/packages/recutils.scm: Use
  `url-fetch' instead of `http-fetch' and `ftp-fetch'.
* distro/packages/bootstrap.scm: Likewise
  (bootstrap-origin): Remove references to `http-fetch' and
  `ftp-fetch'.
* guix.scm (%public-modules): Remove `http' and `ftp'; add `download'.

distro: Split (distro packages base) into several files.

* distro/packages/base.scm (libsigsegv, gawk, perl, m4, gmp, mpfr, mpc,
  ncurses, readline, bash, libtool, libunistring, libffi, pkg-config,
  libgc): Move to modules of their own.
  (guile-1.8, guile-2.0): Move to...
* distro/packages/guile.scm: ... here.

* distro/packages/bash.scm, distro/packages/bdw-gc.scm,
  distro/packages/gawk.scm, distro/packages/libffi.scm,
  distro/packages/libsigsegv.scm, distro/packages/libtool.scm,
  distro/packages/libunistring.scm, distro/packages/m4.scm,
  distro/packages/multiprecision.scm, distro/packages/ncurses.scm,
  distro/packages/perl.scm, distro/packages/pkg-config.scm,
  distro/packages/readline.scm: New files.