Copyright for pngquant source package in Bionic

Format: http://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
Upstream-Contact: Kornel Lesiński 
Source: http://pngquant.org/releases.html

Files: *
Copyright: © 1997-2002 Greg Roelofs 
           © 1989-1991 Jef Poskanzer 
           © 2009-2013 Kornel Lesiński 
License: BSD-2-clause

License: BSD-2-clause
   Permission to use, copy, modify, and distribute this software and its
   documentation for any purpose and without fee is hereby granted, provided
   that the above copyright notice appear in all copies and that both that
   copyright notice and this permission notice appear in supporting
   documentation.  This software is provided "as is" without express or
   implied warranty.
 .
 On Debian systems, the BSD license can be found at /usr/share/common-licenses/

Files: rwpng.*
Copyright: © 1998-2002 Greg Roelofs 
License: BSD-3-clause
   This software is provided "as is," without warranty of any kind,
   express or implied.  In no event shall the author or contributors
   be held liable for any damages arising in any way 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. Redistributions of source code must retain the above copyright
      notice, disclaimer, and this list of conditions.
   2. Redistributions in binary form must reproduce the above copyright
      notice, disclaimer, and this list of conditions in the documenta-
      tion and/or other materials provided with the distribution.
   3. All advertising materials mentioning features or use of this
      software must display the following acknowledgment:
 .
         This product includes software developed by Greg Roelofs
         and contributors for the book, "PNG: The Definitive Guide,"
         published by O'Reilly and Associates.

Files: debian/*
Copyright: © 2005-2008 Nelson A. de Oliveira 
           © 2013 Andreas Tille 
License: BSD-2-clause