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.

build: Pass the appropriate flags when building `libstore.a'.

* daemon.am (libstore_a_CFLAGS): Rename to...
  (libstore_a_CXXFLAGS): ... this.

build-system/gnu: Remove #:path-exclusions parameter.

* guix/build/gnu-build-system.scm (set-paths): Remove `path-exclusions'
  parameter.  Replace `relevant-input-directories' by
  `input-directories'.
* guix/build-system/gnu.scm (gnu-build): Remove `path-exclusions'
  parameter; don't pass it in BUILDER.
* guix/build-system/cmake.scm (cmake-build): Likewise.

Merge branch 'master' into core-updates

Conflicts:
	Makefile.am
	gnu/packages/base.scm

snix: Adjust import to current Nixpkgs input attribute names.

* guix/snix.scm (snix-derivation->guix-package): Use the new names
  `nativeBuildInputs' and `propagatedNativeBuildInputs'.

gnu-maintenance: Improve 'official-gnu-packages'; add related procedures.

* guix/gnu-maintenance.scm (http-fetch): Return an input port.
  (<gnu-package-descriptor>): Add it.
  (official-gnu-packages): Use <gnu-package-descriptor>.
  (find-packages): Add it.
  (gnu-package?): Adjust accordingly.

Add (guix build-system cmake).

* guix/build/cmake-build-system.scm, guix/build-system/cmake.scm: New files.
* Makefile.am (MODULES): Add them.

build: Set `%fresh-auto-compile' in `hydra.scm'.

* hydra.scm: Set `%fresh-auto-compile' to #t.

gnu: make-bootstrap: Import (gnu packages gcc).

* gnu/packages/make-bootstrap.scm: Import (gnu packages gcc).

download: Remove unreliable GNU mirror.

* guix/download.scm (%mirrors)[gnu]: Remove ftp.chg.ru.

gnu: Add libelf.

* gnu/packages/gcc.scm (libelf): New variable.

gnu: Add ISL and CLooG.

* gnu/packages/gcc.scm (%gcc-infrastructure, isl, cloog): New variables.

gnu: Move GCC to its own module.

* gnu/packages/base.scm (gcc-4.7): Move to...
* gnu/packages/gcc.scm: ... here.  New file.
* Makefile.am (MODULES): Add it.

glib: Patch around prlimit(2) failure.

* gnu/packages/glib.scm (glib)[source]: Switch to mirror://gnome.
  [inputs]: Add `patch/tests-prlimit'.
  [arguments]: Add it.
* gnu/packages/patches/glib-tests-prlimit.patch: New file.
* Makefile.am (dist_patch_DATA): Add it.

build: `hydra.scm' changes %load-path to refer to itself.

* hydra.scm: Add `eval-when' clause.

Update `TODO'.

gnu: Add GNU cflow.

* gnu/packages/cflow.scm: New file.
* Makefile.am (MODULES): Add it.

gnu: Add GNU cppi.

* gnu/packages/cppi.scm: New file.
* Makefile.am (MODULES): Add it.

store: Really disable file name canonicalization for derivation inputs.

* guix/store.scm (write-contents)[call-with-binary-input-file]: Set
  %FILE-PORT-NAME-CANONICALIZATION to #f.
* gnu/packages.scm (search-patch, search-bootstrap-binary): Leave
  %FILE-PORT-NAME-CANONICALIZATION unchanged.  This reverts 9776ebb.

store: Use `sendfile' when available.

* guix/store.scm (write-contents)[call-with-binary-input-file]: New
  procedure.
  Use `sendfile' instead of `dump' when available.  Add `size'
  parameter.
  (write-file): Update caller.