Ditto
Boost Software License Version 1.0. See LICENSE_BOOST.txt for details. Alternatively, this file may be distributed under the terms of the Tango 3-Clause BSD License (see LICENSE_BSD.txt for details).
Copyright (c) 2009-2016 dunnhumby Germany GmbH. All rights reserved.
A log layout that only displays the message and no extra data such as the date, level, etc