#1 Add Sequence protection

[Markus Moeller]

I think in the InitializeSecurityContext and
gss_init_sec_context calls you should add the
ISC_REQ_SEQUENCE_DETECT and
GSS_C_SEQUENCE_FLAG respectivily.

The replay protection doesn't cover packets out of
sequence, whereas out of sequence rotection should
cover replay protection.

Regards
Markus