[#67] node: Accept expired locked objects

Allow replication of any (expired too) locked object. Information about
object locking is considered to be presented on the _container nodes_.

Signed-off-by: Pavel Karpy <p.karpy@yadro.com>

pkg/services/object/put/local.go

@@ -20,6 +20,8 @@ type ObjectStorage interface {
 	// Lock must lock passed objects
 	// and return any appeared error.
 	Lock(locker oid.Address, toLock []oid.ID) error
+	// IsLocked must clarify object's lock status.
+	IsLocked(oid.Address) (bool, error)
 }
 
 type localTarget struct {