Try to get security=domain at least slightly working.

Try to get security=domain at least slightly working.

The previous code both had basic logic flaws in it, and some subtle
issues regarding the Win2k info3 response.

I've tested this against Samba (it looks like that was missed last time
due to the 'called name' corruption - which broke my testsuite) and
accomidated what I've seen from a info3 printout jmcd gave me.

I'll get this tested fully as soon as I get my VMware going again.

Andrew Bartlett
(This used to be commit 87eba4c811293d2428bfb9bc36de22e66dce7f8b)