s4:samr RPC server - QueryDisplayInfo returns always all domains users, aliases and...

s4:samr RPC server - QueryDisplayInfo returns always all domains users, aliases and groups

That means when calling "QueryDisplayInfo" on the BUILTIN handle we
still get all related domain objects - for example all domain (global
+ universal) groups. This is contrary to the "EnumDomain..." calls which
do really only return the objects in the specified domain policy handle.

This has been observed against Windows Server 2008 and confirmed by
dochelp.

In the same occasion I've converted from a "gendb*"-oriented search call to "dsdb_search".

Patch-reviewed-by: Andrew Tridgell <tridge@samba.org>