Added API layer for scale-in and scale-out support
Added API layer for scale-in and scale-out support

tengqm/senlin,tengqm/senlin-container,tengqm/senlin-container,stackforge/senlin,openstack/senlin,Alzon/senlin,openstack/senlin,tengqm/senlin,Alzon/senlin,openstack/senlin,stackforge/senlin