Copyright for casper source package in Focal

Author: Tollef Fog Heen 
        Matt Zimmerman 
        Colin Watson 

Copyright:

License (casper-md5check/md5.c, casper-md5check/md5,h}):

	Copyright (C) 1999-2002 Aladdin Enterprises
	All rights reserved.

	This software is provided 'as-is', without any express or implied
	warranty.  In no event will the authors be held liable for any damages
	arising from the use of this software.

	Permission is granted to anyone to use this software for any purpose,
	including commercial applications, and to alter it and redistribute it
	freely, subject to the following restrictions:

	1. The origin of this software must not be misrepresented; you must not
	   claim that you wrote the original software. If you use this software
	   in a product, an acknowledgment in the product documentation would be
	   appreciated but is not required.

	2. Altered source versions must be plainly marked as such, and must not
	   be misrepresented as being the original software.

	3. This notice may not be removed or altered from any source
	   distribution.

License (bin/casper-set-selections):

	The Debian installer preseeder is copyright 2004 by Joey Hess
	 and others.

	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
	(at your option) any later version.

License (everything else):

	Copyright (C) 2006 Marco Amadori 
	Copyright (C) 2005-2011 Canonical Ltd. 
	Copyright (C) 2008 Dell Inc.

	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
	(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.

	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 St, Fifth Floor, Boston, MA 02110-1301 USA

On Debian and Ubuntu systems, the complete text of the GNU General Public License
can be found in /usr/share/common-licenses/GPL file.