AD: Add autofs provider
https://fedorahosted.org/sssd/ticket/1632
Adds the possibility to configure:
autofs_provider = ad
The AD autofs provider uses the rfc2307 (nis*) attribute maps. This is
different (at the moment) from using autofs_provider=ldap with
ldap_schema=ad.
Reviewed-by: Ondrej Valousek <ondrejv2@fedoraproject.org>
Reviewed-by: Pavel Březina <pbrezina@redhat.com>