busybox

tar compability modes for dpkg

I've found couple of deb files which require old tar compability modes
to be unpacked. This patch allows me to enable them for dpkg without
enabling tar.

Signed-off-by: Kim B. Heino <Kim.Heino@bluegiga.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>