in ntlmv2, the client will retry the challenge response trying a bunch
of different domain names assuming the same server challenge. so we have
to make retries work with factotum and the auth server.
also, windows 7 with compatlevel=4 sends all zeros LM response.
extending factotums and the auth servers mschap implementation
to handle variable length NT response for NTLMv2.
fix some minor bugs.
only tested with cifs so far.
