add docker server version to /info

Signed-off-by: Zhang Kun <zkazure@gmail.com>

api/client/info.go

@@ -35,6 +35,7 @@ func (cli *DockerCli) CmdInfo(args ...string) error {
 
 	fmt.Fprintf(cli.out, "Containers: %d\n", info.Containers)
 	fmt.Fprintf(cli.out, "Images: %d\n", info.Images)
+	fmt.Fprintf(cli.out, "Engine Version: %s\n", info.ServerVersion)
 	ioutils.FprintfIfNotEmpty(cli.out, "Storage Driver: %s\n", info.Driver)
 	if info.DriverStatus != nil {
 		for _, pair := range info.DriverStatus {

api/types/types.go

@@ -215,6 +215,7 @@ type Info struct {
 	Name               string
 	Labels             []string
 	ExperimentalBuild  bool
+	ServerVersion      string
 }
 
 // ExecStartCheck is a temp struct used by execStart