Merge the core and python tests in the tests/ directory

* tests/: Rename as...
* tests/core/: ... this.
* python/tests/: Rename as...
* tests/python/: ... this.
* python/tests/run.in: Move as...
* tests/run.in: This, and adjust.
* tests/Makefile.am: Adjust to run both core and python tests.
* configure.ac, README, debian/python3-spot.examples, debian/rules,
doc/org/tut.org, python/Makefile.am, spot/ltsmin/Makefile.am,
spot/ltsmin/kripke.test, spot/sanity/ipynb.test: Adjust.

tests/core/tunenoform.test

@@ -0,0 +1,41 @@
+#! /bin/sh
+# -*- coding: utf-8 -*-
+# Copyright (C) 2009, 2014 Laboratoire de Recherche et Développement
+# de l'Epita (LRDE).
+# Copyright (C) 2003 Laboratoire d'Informatique de Paris 6 (LIP6),
+# département Systèmes Répartis Coopératifs (SRC), Université Pierre
+# et Marie Curie.
+#
+# 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/>.
+
+
+# Check for unabbreviate_ltl + negative_normal_form visitors
+
+. ./defs || exit 1
+
+set -e
+
+cat >tunenoform.txt<<EOF
+!(a ^ b), (a|!b) & (!a|b)
+!(a <=> b), (a|b) & (!a|!b)
+!(a => b), a&!b
+!(!a => !b), !a&b
+!Fa, false R !a
+!G!a, true U a
+!(GF a => FG b), (0 R (1 U a)) & (0 R (1 U !b))
+EOF
+
+run 0 ../tunenoform tunenoform.txt