r2753: Workaround for the (rather broken) _samr_query_useraliases rpc-call.

r2753: Workaround for the (rather broken) _samr_query_useraliases rpc-call.

_samr_query_useraliases shows up with all kind of very weird memberships
(global-groups, machine-accounts, etc.). Sometimes even if there is no
alias-membership at all.

One of the biggest mistakes is to convert any unix-group the user is a
member of, into an alias by default in get_group_from_gid.

get_alias_user_groups should be rewritten to use
pdb_enum_alias_memberships.

Guenther
(This used to be commit 73ab2d2a74d3992167d9304dd41f60ad0805dd67)