Passing pod UUID to Kubelet.

We need UUID to indicate the instance of a Pod to make restart work. 
It does matter if we want to have some in-place update for container config. For example, changing container's cpu limit, which results a hash value you proposed change. In this case, should we just simply update docker container's config without killing the existing one? I know we don't support this today, but in a long run, I believe we will add those logic here. We did the similar thing in our internal system. 

Also in my mind this UUID could be changed to any other identifier for BoundPod in a long run, not necessary as today's UUID format. In that case, I think keep the identifier of a BoundPod is a clean way to go.