[Tracker] Live Container Updates

[vbatts]

https://github.com/opencontainers/specs/blob/master/ROADMAP.md#live-container-updates

This needs to be an optional feature.
and per the life-cycle discussions, this is left to the operator where hooks that would happen after the "start" action of the container.

[hqhq]

Related discussion: https://groups.google.com/a/opencontainers.org/forum/#!topic/dev/mWZVREVL9T8

[wking]

Cross referencing earlier discussion in #17.