libcli/auth: set the return_authenticator->timestamp = 0

This is what windows returns, the value is ignored by the client anyway.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
libcli/auth: remove bogus comment regarding replay attacks

creds->sequence (timestamp) is the value that is used to increment the internal
state, it's not a real sequence number. The sequence comes
from adding all timestamps of the whole session.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
libcli/auth: try to use the current timestamp creds->sequence

If the last usage of netlogon_creds_client_authenticator()
is in the past try to use the current timestamp and increment
more than just 2.

If we use netlogon_creds_client_authenticator() a lot within a
second, we increment keep incrementing by 2.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>

Autobuild-User(master): Stefan Metzmacher <metze@samba.org>
Autobuild-Date(master): Tue Dec 24 13:18:18 CET 2013 on sn-devel-104