Merge of server-side authentication changes to 3.0:

Merge ... server-side authentication changes to 3.0:

 - user_ok() and user_in_group() now take a list of groups, instead of
   looking for the user in the members of all groups.

 - The 'server_info' returned from the authentication is now kept around
  - in future we won't copy the sesion key, username etc, we will just
    referece them directly.

 - rhosts upgraded to use the SAM if possible, otherwise fake up based on
   getpwnam().

 - auth_util code to deal with groups upgraded to deal with non-winbind domain
   members again.

Andrew Bartlett
(This used to be commit 74b5436c75114170ce7c780c19226103d0df9060)