Core: made update_status used address for addressing to node.
Python: added new interface for supporting multibackends. Used elliptics.Address where it can be used and removed duplicating interfaces. Added new abilities to elliptics.RouteList for working with backend_id.
Merge branch 'multibackend' of github.com:reverbrain/elliptics into multibackend
Python: fixed dnet_balancer and for working with new multibackends route list.
Recovery: made dnet_recovery works with new multibackends route list.
Added ability to specifies backend_id (via '-i') when dnet_recovery runs for one node ('--one-node')