maint: Add copyright notices for the build system.

* configure.ac: Add copyright notice.
* Makefile.am: Likewise.

Makefile.am

 ## Process this file with automake to produce Makefile.in.
 
+# Copyright © 1995-2016 Free Software Foundation, Inc.
+# Copyright © 2016 Mathieu Lirzin <mthl@gnu.org>
+#
+# This file is part of Cuirass.
+#
+# Cuirass 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 2, or (at your option)
+# any later version.
+#
+# Cuirass 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 Cuirass.  If not, see <http://www.gnu.org/licenses/>.
+
 # Guile local load paths.
 local_load_path = "$(abs_top_builddir)/src:$(abs_top_srcdir)/src"
 local_load_compiled_path = "$(abs_top_builddir)/src"

configure.ac

+## Process this file with autoconf to produce a configure script.
+
+# Copyright © 2016 Mathieu Lirzin <mthl@gnu.org>
+#
+# This file is part of Cuirass.
+#
+# Cuirass 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 2, or (at your option)
+# any later version.
+#
+# Cuirass 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 Cuirass.  If not, see <http://www.gnu.org/licenses/>.
+
 AC_PREREQ([2.61])
 AC_INIT([Cuirass], [0.0.1], [bug-guix@gnu.org])
 AC_CONFIG_SRCDIR([bin/cuirass.in])