Enhancing --cluster-advertise to support <interface-name>

--cluster-advertise daemon option is enahanced to support <interface-name>
in addition to <ip-address> in order to amke it  automation friendly using
docker-machine.

Signed-off-by: Madhu Venugopal <madhu@docker.com>

Conflicts:
	integration-cli/docker_cli_info_test.go

api/client/info.go

@@ -107,5 +107,8 @@ func (cli *DockerCli) CmdInfo(args ...string) error {
 		fmt.Fprintf(cli.out, "Cluster store: %s\n", info.ClusterStore)
 	}
 
+	if info.ClusterAdvertise != "" {
+		fmt.Fprintf(cli.out, "Cluster advertise: %s\n", info.ClusterAdvertise)
+	}
 	return nil
 }

api/types/types.go

@@ -219,6 +219,7 @@ type Info struct {
 	ExperimentalBuild  bool
 	ServerVersion      string
 	ClusterStore       string
+	ClusterAdvertise   string
 }
 
 // ExecStartCheck is a temp struct used by execStart