* Add docker pullable support.

* Fix inspect image bug.
* Fix remove image bug.

pkg/kubelet/dockershim/docker_container_test.go

@@ -105,7 +105,7 @@ func TestContainerStatus(t *testing.T) {
 	ct, st, ft := dt, dt, dt
 	state := runtimeApi.ContainerState_CREATED
 	// The following variables are not set in FakeDockerClient.
-	imageRef := ""
+	imageRef := DockerImageIDPrefix + ""
 	exitCode := int32(0)
 	var reason, message string