kbuild, deb-pkg: generate debian/copyright file

On Thursday 23 April 2009, Frans Pop wrote:
Add a basic debian/copyright to the binary packages.

Based on an earlier patch from Maximilian Attems.

Signed-off-by: Frans Pop <elendil@planet.nl>
Acked-by: maximilian attems <max@stro.at>
Cc: Andres Salomon <dilinger@debian.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>