r4331: Implement SAMR query_dom_info-call info-level 8 server- and client-side,

r4331: Implement SAMR query_dom_info-call info-level 8 server- and client-side,
based on samba4-idl.

This saves us an enormous amount of totally unnecessary ldap-traffic
when several hundreds of winbind-daemons query a Samba3 DC just to get
the fake SAM-sequence-number (time(NULL)) by enumerating all users, all
groups and all aliases when query-dom-info level 2 is used.

Note that we apparently never get the sequence number right (we parse a
uint32, although it's a uint64, at least in samba4 idl). For the time
being, I would propose to stay with that behaviour.

Guenther