Logging improvement (UID, net-attach-def)

This change adds pod UID and net-attach-def name in verbose log
and sends kubernetes event when net-attach-def is not found.

testing/testing.go

@@ -149,6 +149,7 @@ func NewFakePod(name string, netAnnotation string, defaultNetAnnotation string)
 		ObjectMeta: metav1.ObjectMeta{
 			Name:      name,
 			Namespace: "test",
+			UID:       "testUID",
 		},
 		Spec: v1.PodSpec{
 			Containers: []v1.Container{