Copyright for partman-crypto source package in Xenial

Copyright 2005-2006 by Max Vozeler , based on work by
Anton Zinoviev.

blockdev-wipe/blockdev-wipe.c is
Copyright (C) 2006 David Härdeman 

This package is licensed under the GNU General Public License version 2,
or any later version at your option. On Debian systems, the GPL is
available in /usr/share/common-licenses/GPL.