Update license to GPLv3.

Author: bhaible

build-aux/config.libpath

@@ -6,19 +6,18 @@
 #   Taken from GNU libtool, 2003
 #   Originally by Gordon Matzigkeit <gord@gnu.ai.mit.edu>, 1996
 #
-#   This program is free software; you can redistribute it and/or modify
+#   This program 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 of the License, or
+#   the Free Software Foundation; either version 3 of the License, or
 #   (at your option) any later version.
 #
-#   This program 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.
+#   This program 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, write to the Free Software Foundation,
-#   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 #   As a special exception to the GNU General Public License, if you
 #   distribute this file as part of a program that contains a

build-aux/reloc-ldflags

@@ -5,19 +5,18 @@
 #   Copyright 2003 Free Software Foundation, Inc.
 #   Written by Bruno Haible <bruno@clisp.org>, 2003.
 #
-#   This program is free software; you can redistribute it and/or modify
+#   This program 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 of the License, or
+#   the Free Software Foundation; either version 3 of the License, or
 #   (at your option) any later version.
 #
-#   This program 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.
+#   This program 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, write to the Free Software Foundation,
-#   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 #   As a special exception to the GNU General Public License, if you
 #   distribute this file as part of a program that contains a