* po/doc/contributing.pot: New file.
* po/doc/guix.pot: New file.
* po/doc/local.mk: New file.
* Makefile.am: Include it. Add gettext command. Add silent rules for po4a.
* configure.ac: Look for po4a-translate and po4a-updatepo.
* doc/local.mk: Add rules to generate translated texi files.
(TRANSLATED_INFO): New variable.
(BUILT_SOURCES, EXTRA_DIST, MAINTAINERCLEANFILES): Add it.
* .gitignore: Add generated files.
* doc/local.mk: Use "%D%" for the directory of the fragment relative to
the base 'Makefile.am'.
* emacs/local.mk: Likewise.
* gnu/local.mk: Likewise.
* nix/local.mk: Likewise.
This follows a convention used by some other GNU packages like Autoconf,
Bison, Coreutils, and Gnulib.
* doc.am: Rename to ...
* doc/local.mk: ... this.
* emacs.am: Rename to ...
* emacs/local.mk: ... this.
* gnu-system.am: Rename to ...
* gnu/local.mk: ... this.
* daemon.am: Rename to ...
* nix/local.mk: ... this.
* Makefile.am: Adapt to them.
* doc/guix.texi (Porting to a New Platform): Adapt documentation.
* guix/config.scm.in (%state-directory, %config-directory): Adapt comments.
* emacs/guix-config.el.in (guix-config-state-directory): Likewise.