busybox

Simplify copyright/license notice that appears in the binary.

Existing copyright notice for binary would need to be longer to achieve
optimal accuracy.  This compromise punts to the source for full notices,
but does note the years of the copyrights and that there are many authors,
all licensing under GPLv2.

Signed-off-by: Bradley M. Kuhn <bkuhn@ebb.org>
Signed-off-by: Tony Sebro <tony@sfconservancy.org>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>