org: syntax-highlight the HOA outputs

* elisp/hoa-mode.el, elisp/Makefile.am, elisp/README: New files.
* debian/copyright, configure.ac, README, Makefile.am: Adjust.
* doc/org/init.el.in: Adjust to load hoa-mode.el.
* doc/org/spot.css: Add entries for HOA mode.
* doc/org/hoa.org, doc/org/ltldo.org, doc/org/oaut.org,
doc/org/tut20.org, doc/org/tut21.org, doc/org/tut22.org,
doc/org/tut30.org: Make the HOA outputs as HOA.

elisp/Makefile.am

@@ -0,0 +1,27 @@
+## -*- coding: utf-8 -*-
+## Copyright (C) 2015 Laboratoire de Recherche et Développement de
+## l'Epita (LRDE).
+##
+## This file is part of Spot, a model checking library.
+##
+## Spot is free software; you can redistribute it and/or modify it
+## under the terms of the GNU General Public License as published by
+## the Free Software Foundation; either version 3 of the License, or
+## (at your option) any later version.
+##
+## Spot is distributed in the hope that it will be useful, but WITHOUT
+## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+## or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+## License for more details.
+##
+## You should have received a copy of the GNU General Public License
+## along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+EXTRA_DIST = hoa-mode.el
+
+GIT = https://gitlab.lrde.epita.fr/spot/emacs-modes/raw/master/
+
+.PHONY: update-el
+update-el:
+	wget $(GIT)/hoa-mode.el -O $(srcdir)/hoa-mode.el
+	chmod a-w $(srcdir)/hoa-mode.el