Copyright for ent source package in Sid

Package Maintainers:
  Thorsten Alteholz  from Tue,  2 Jun 2012 18:00:00 +0200
  Wesley J. Landaker  from Sun,  5 Sep 2004 08:25:33 -0600
  Emanuele Rocca         from Sun, 16 Nov 2003 17:30:41 +0100
  Viral Shah           from Fri, 26 Oct 2001 23:04:21 -0600.

Upstream Author: John Walker
Upstream Homepage: 

Copyright:

  This software is in the public domain.  Permission to use, copy,
  modify, and distribute this software and its documentation for any
  purpose and without fee is hereby granted, without any conditions or
  restrictions.  This software is provided "as is" without express or
  implied warranty.

(The Debian packaging is released under this same license.)