r1061: The start of the SamLogon call for the NETLOGON pipe.

r1061: The start of the SamLogon call for the NETLOGON pipe.

Changes:

- Check for a valid 'pipe_state' in netr_ServerAuthenticate3 before
  we dereference it

- removes the expansionroom[7] in the netr_SamInfo* structs to 7
individual elements.
- renames netr_SamInfo -> netr_SamInfo2
          netr_SamInfo2 -> netr_SamInfo3
  - Having the thing we always called an 'info3' being 'netr_SamInfo2'
    was just too confusing.

- Expand and fill in extra details about users from the SAM, into
  the server_info, for processing into the SamLogon reply.

- Add a dum_sid_dup() function to duplicate a struct dom_sid

The SamLogon code currently does not return supplementary groups, and is
only tested with Samba4 smbtorture.

Andrew Bartlett