s4-torture: Add oplock break retry tests - test2

s4-torture: Add oplock break retry tests - test2

Test to see if oplock break retries are sent by the server.
Also checks to see if new channels can be created and used
after an oplock break retry.

The test by default blocks channels by ignoring incoming lease break
requests on that channel. This does not work when testing against a
windows server.
Use --option=torture:use_iptables=true to use iptables to block ports
instead when testing against windows servers.

Signed-off-by: Guenther Deschner <gd@samba.org>
Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Jeremy Allison <jra@samba.org>