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.

distro: Search bootstrap binaries and patches in %LOAD-PATH.

* Makefile.am (patchdir, bootstrapdir): Change to be sub-directories of
  $(guilemoduledir).
  (.scm.go): Remove `DISTRO_' environment variables.
* distro.scm (not-colon): Remove.
  (%patch-path, %bootstrap-binaries-path): Default to sub-directories of
  the entries in %LOAD-PATH.
* pre-inst-env.in: Remove definition of `DISTRO_' environment variables.

build: Produce (guix config) instead of using compile-time tricks.

* guix/config.scm.in: New file.
* guix/utils.scm: Use it.
  (%libgcrypt): Remove.
  (%nixpkgs-directory): Don't capture the compile-time $NIXPKGS; use
  %NIXPKGS instead.
  (nixpkgs-derivation): Use %NIX-INSTANTIATE.
* pre-inst-env.in (NIX_INSTANTIATE, NIXPKGS, LIBGCRYPT): Remove.

* configure.ac: Emit `guix/config.scm'.
* Makefile.am (GOBJECTS): Add `guix/config.go'.
  (nobase_nodist_guilemodule_DATA): Add `guix/config.scm'.

build: Fix out-of-source-tree builds.

* Makefile.am (distro/packages/bootstrap/x86_64-linux/guile-bootstrap-2.0.6.tar.xz,
  distro/packages/bootstrap/i686-linux/guile-bootstrap-2.0.6.tar.xz):
  Make the target's parent directory.
* pre-inst-env.in (DISTRO_BOOTSTRAP_PATH): Add the builddir-relative
  directory.

distro: Change $DISTRO_{PATCH,BOOTSTRAP}_DIRECTORY to search paths.

* distro.scm (not-colon): New variable.
  (%patch-directory): Rename to...
  (%patch-path): ... this.  Turn into a list.  Expect $DISTRO_PATCH_PATH
  to be a colon-separated search path.
  (%bootstrap-binaries-directory): Rename to...
  (%bootstrap-binaries-path): ... this.  Likewise.
  (search-patch, search-bootstrap-binary): Adjust accordingly.

* pre-inst-env.in: Change to use `DISTRO_PATCH_PATH' and
  `DISTRO_BOOTSTRAP_PATH'.

build: Move `distro/patches' to `distro/packages/patches'.

* distro/patches: Move directory to...
* distro/packages/patches: ... here.
* Makefile.am (dist_patch_DATA): Adjust accordingly.
* pre-inst-env.in (DISTRO_PATCH_DIRECTORY): Likewise.

distro: Use our own pre-built Guile to bootstrap.

* distro/packages/base.scm (%bootstrap-guile): Build from a tarball
  containing a pre-built Guile.

* distro.scm (%bootstrap-binaries-directory): New variable.
  (search-bootstrap-binary): New procedure.

* Makefile.am (bootstrapdir, bootstrap_x86_64_linuxdir,
  dist_bootstrap_x86_64_linux_DATA, DISTCLEANFILES, DOWNLOAD_FILE): New
  variables.
  (distro/packages/bootstrap/x86_64-linux/guile-bootstrap-2.0.6.tar.xz):
  New rule.
  (EXTRA_DIST): Add `build-aux/download.scm'.
  (.scm.go): Define the `DISTRO_BOOTSTRAP_DIRECTORY' and
  `DISTRO_INSTALLED_BOOTSTRAP_DIRECTORY' environment variables.

* pre-inst-env.in: Define `DISTRO_BOOTSTRAP_DIRECTORY'.

* build-aux/download.scm: New file.
* distro/packages/bootstrap/x86_64-linux/{bash, mkdir, tar, xz}: New
  files.

Add `pre-inst-env' script.

* pre-inst-env.in: New file.
* configure.ac: Add it to `AC_CONFIG_FILES' and `AC_CONFIG_COMMANDS'.