CIFS ntlm authentication and signing - Build a proper av/ti pair blob for ntlmv2...

Build an av pair blob as part of ntlmv2 (without extended security) auth
request.  Include netbios and dns names for domain and server and
a timestamp in the blob.

Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Jeff Layton <jlayton@samba.org>
Signed-off-by: Steve French <sfrench@us.ibm.com>