gnu: mozjs: Mark as unsupported on mips64el-linux.

* gnu/packages/gnuzilla.scm (mozjs)[supported-systems]: New field.

gnu: gpgme: Build against GnuPG 2.0.

* gnu/packages/gnupg.scm (gpgme)[inputs]: Change to GNUPG-2.0.

environment: Move iteration outside of 'for-each-search-path'.

* guix/search-paths.scm (search-path-definition): New procedure.
* guix/scripts/environment.scm (for-each-search-path): Rename to...
  (evaluate-input-search-paths): ... this.  Remove 'proc' and 'pure?'
  parameters, and return directly the list of search-path/value pairs.
  (create-environment): Use 'for-each' and 'evaluate-input-search-paths'
  instead of 'for-each-search-path'.
  (show-search-paths): Use 'for-each', 'search-path-definition', and
  'evaluate-search-paths' instead of 'for-each-search-path'.

environment: Use 'evaluate-search-paths'.

This allows 'guix environment' to correctly handle non-directory
and/or pattern search-path specifications, such as that for
'XML_CATALOG_FILES'.

* guix/scripts/environment.scm (for-each-search-path): Use
  'evaluate-search-paths' instead of 'search-path-as-list' & co.

search-paths: Define the 'PATH' environment variable.

* guix/search-paths.scm ($PATH): New variable.
* guix/scripts/environment.scm (for-each-search-path): Use it.

search-paths: 'evaluate-search-paths' can be passed a list of directories.

* guix/search-paths.scm (evaluate-search-paths): Change 'directory' to
  'directories', and adjust 'search-path-as-list' accordingly.
* guix/scripts/package.scm (search-path-environment-variables): Adjust
  call accordingly.

gnu-maintenance: 'gnu-package?' returns #t for R and for GNOME packages.

Reported by John Darrington.

* guix/gnu-maintenance.scm (gnu-package?)[mirror-type]: Add "gnome" to
  the list of GNU mirrors.  Return #f for "cran".

environment: Use (guix search-paths).

* guix/scripts/environment.scm: Use (guix search-paths).  Fixes a
  regression introduced in e89431b.

gnu: vcftools: Remove "-m64" from CFLAGS.

* gnu/packages/bioinformatics.scm (vcftools): Explicitly set CFLAGS to
  remove "-m64" flag.

gnu: fltk: Fix undefined symbol errors for shared libraries.

* gnu/packages/patches/fltk-shared-lib-defines.patch: New patch.
* gnu-system.am (dist_patch_DATA): Add it.
* gnu/packages/fltk.scm (source)[patches]: New field.

gnu: ardour: Add library dirs to RUNPATH.

* gnu/packages/audio.scm (ardour)[arguments]: Add a build phase to add all
  library output directories to the rpath using linker flags.

gnu: Add bluez.

* gnu/packages/linux.scm (bluez): New variable.

gnu: Add libical.

* gnu/packages/calendar.scm: New file.
* gnu-system.am (GNU_SYSTEM_MODULES): Add it.

gnu: Add soil.

* gnu/packages/gl.scm (soil): New variable.

records: Make 'make-syntactic-constructor' available at load/eval/expand.

* guix/records.scm (make-syntactic-constructor): Wrap in 'eval-when'.

profiles: Use a &message error condition instead of 'error'.

* guix/profiles.scm (sexp->manifest): Use 'raise' instead of 'error'.

search-paths: 'evaluate-search-paths' now returns spec/value pairs.

* guix/search-paths.scm (evaluate-search-paths): Return
  specification/value pairs instead of variable/value pairs.
* guix/scripts/package.scm (search-path-environment-variables): Adjust
  accordingly.  Pass #:separator to 'environment-variable-definition'.

search-paths: Add 'environment-variable-definition'.

* guix/search-paths.scm (environment-variable-definition): New variable.
* guix/scripts/package.scm (search-path-environment-variables): Use it.

search-paths: Add 'evaluate-search-paths', from (guix scripts package).

* guix/scripts/package.scm (with-null-error-port,
  evaluate-search-paths): Move to...
* guix/search-paths.scm: ... here.
* guix/utils.scm (string-tokenize*): Move to...
* guix/search-paths.scm: ... here.
* tests/utils.scm ("string-tokenize*"): Adjust accordingly.

Move search path specifications to (guix search-paths).

* guix/packages.scm (<search-path-specification>,
  search-path-specification->sexp, sexp->search-path-specification):
  Move to...
* guix/search-paths.scm: ... here.  New file.
* Makefile.am (MODULES): Add it.
* guix/build-system/cmake.scm, guix/build-system/glib-or-gtk.scm,
  guix/build-system/gnu.scm, guix/build-system/haskell.scm,
  guix/build-system/perl.scm, guix/build-system/python.scm,
  guix/build-system/ruby.scm, guix/build-system/waf.scm,
  guix/profiles.scm, guix/scripts/package.scm: Use it.