gnu: Add Guile-RSVG.

* gnu/packages/gtk.scm (guile-rsvg): New variable.
* gnu/packages/patches/guile-rsvg-pkgconfig.patch: New file.
* gnu-system.am (dist_patch_DATA): Add it.

gnu: Add frescobaldi.

* gnu/packages/music.scm (frescobaldi): New variable.

gnu: Add python-ly.

* gnu/packages/python.scm (python-ly): New variable.

gnu: Add python-poppler-qt4.

* gnu/packages/pdf.scm (python-poppler-qt4): New variable.

gnu: Add poppler-qt4.

* gnu/packages/pdf.scm (poppler-qt4): New variable.

gnu: Add ruby-thor.

* gnu/packages/ruby.scm (ruby-thor): New variable.

gnu: Add ruby-xml-simple.

* gnu/packages/ruby.scm (ruby-xml-simple): New variable.

gnu: Add ruby-orderedhash.

* gnu/packages/ruby.scm (ruby-orderedhash): New variable.

gnu: Add ruby-atoulme-antwrap.

* gnu/packages/ruby.scm (ruby-atoulme-antwrap): New variable.

gnu: Add ruby-rjb.

* gnu/packages/ruby.scm (ruby-rjb): New variable.

gnu: Add ruby-builder.

* gnu/packages/ruby.scm (ruby-builder): New variable.

gnu: libedit: Enable wide character support.

* gnu/packages/libedit.scm (libedit)[arguments]: Add "--enable-widec" to
  configure flags.

gnu: libedit: Update to 20150325-3.1.

* gnu/packages/libedit.scm (libedit): Update to 20150325-3.1.

build: Add R build system.

* guix/build-system/r.scm: New file.
* guix/build/r-build-system: New file.
* Makefile.am (MODULES): Add new files.
* doc/guix.texi (Build Systems): Document r-build-system.

import: Add 'cran' importer.

* guix/import/cran.scm: New file.
* guix/scripts/import.scm: Add "cran" to 'importers'.
* guix/scripts/import/cran.scm: New file.
* tests/cran.scm: New file.
* Makefile.am (MODULES): Add 'guix/import/cran.scm' and
  'guix/scripts/import/cran.scm'.
  (SCM_TESTS): Add 'tests/cran.scm'.
* doc/guix.texi (Invoking guix import): Document it.
* po/guix/POTFILES.in: Add 'guix/scripts/import/cran.scm'.

emacs: Use only one guix-load-path variable.

emacs/guix-init.el (guix-load-path): Move to ...
emacs/guix-backend.el (guix-load-path): ... Here. Redefine it.

emacs: Fix guix-guile-program default value.

Fixes <http://bugs.gnu.org/21127>.

* emacs/guix-backend.el: Use guix-config.
  (guix-guile-program): Move to ...
* emacs/guix-config.el.in (guix-guile-program): ... here.  Use Guile
  program file name from compile-time instead of depending on PATH.

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

* emacs/guix-{init,profiles}.el.in: Rename to ...
* emacs/guix-{init,profiles}.el: ... these.  New files.
  Use 'guix-config'.
* emacs/guix-config.el.in: New file.
* emacs.am (nodist_lisp_DATA): Add it.  Move them to ...
  (ELFILES): ... here.
* .gitignore, configure.ac: Adjust accordingly.

emacs: Use prompt for packages instead popup for edit action.

* emacs/guix-base.el (guix-package-location): New function.
  (guix-edit-package): Rename and move to ...
* emacs/guix.el (guix-edit): ...here.  Make it interactive.
* emacs/guix-command.el (guix-edit-action): New function (alias to
  'guix-edit') to override the popup for edit command in "M-x guix".
* emacs/guix-list.el (guix-list-edit-package): Adjust for 'guix-edit'
  renaming.
* emacs/guix-main.scm (package-location-string): Allow to accept package
  id or package name as argument.

emacs: Add popup interface for guix commands.

* emacs/guix-command.el: New file.
* emacs.am (ELFILES): Add it.
* doc/emacs.texi (Emacs Initial Setup): Mention 'magit-popup' library.
  (Emacs Popup Interface): New node.
  (Emacs Interface): Add it.
* doc/guix.texi (Top): Likewise.