settings: handle multiple objects/interfaces

Handle the fact that a settings object can now implement multiple
interfaces, and also the fact that multiple settings objects
can implement the same interface.

Change-Id: Icf55b08fe2d355a10f7007489dfddb128e05d90e
Signed-off-by: Deepak Kodihalli <dkodihal@in.ibm.com>
4 files changed