Change the target filter to be multivalued.
Make the `type` option on permissions set location and an
(objectclass=...) targetfilter, instead of location and target.
Make changing or unsetting `type` remove existing
(objectclass=...) targetfilters only, and similarly,
changing/unsetting `memberof` to remove (memberof=...) only.
Update tests
Part of the work for: https://fedorahosted.org/freeipa/ticket/4074
Reviewed-By: Martin Kosek <mkosek@redhat.com>