clean-up header and set the modfiel appropriately

solenv/gbuild/extensions/post_AuxTargets.mk

-#   -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
-#  
+# -*- Mode: makefile-gmake; tab-width: 4; indent-tabs-mode: t -*-
+#
 #   Version: MPL 1.1 / GPLv3+ / LGPLv3+
-#  
+#
 #   The contents of this file are subject to the Mozilla Public License Version
 #   1.1 (the "License"); you may not use this file except in compliance with
 #   the License or as specified alternatively below. You may obtain a copy of
 #   the License at http://www.mozilla.org/MPL/
-#  
+#
 #   Software distributed under the License is distributed on an "AS IS" basis,
 #   WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 #   for the specific language governing rights and limitations under the
 #   License.
-#  
+#
 #   Major Contributor(s):
 #   [ Copyright (C) 2011 Bjoern Michaelsen <bjoern.michaelsen@canonical.com> (initial developer) ]
-#  
+#
 #   All Rights Reserved.
-#  
+#
 #   For minor contributions see the git repository.
-#  
+#
 #   Alternatively, the contents of this file may be used under the terms of
 #   either the GNU General Public License Version 3 or later (the "GPLv3+"), or
 #   the GNU Lesser General Public License Version 3 or later (the "LGPLv3+"),