Copyright for rootskel source package in Xenial

This is a root filesystem skeleton for the Debian/GNU Linux installer.

Author(s): David Whedon, 

Copyright 2001-2007 David Whedon  and the Debian installer
team.

The copyright of this package is GPL, version 2 or later.

console-type.c:
    adapted for Debian Installer by Frans Pop  from
    cttyhack from busybox 1.11; licenced under GPL version 2, and:
    Copyright (c) 2007 Denys Vlasenko 

steal-ctty.c:
    adapted for Debian Installer by Jérémy Bobbio  from
    cttyhack from busybox 1.11; licenced under GPL version 2, and:
    Copyright (c) 2007 Denys Vlasenko