Live Container Updates

Tag this thread, which is in the early stages of collecting a thought
that has been kicking around informally for a while (e.g. lots of
"yeah, that would be nice" comments in meetings [1,2]).

[1]: https://github.com/opencontainers/specs/wiki/MeetingMinutes:-2015-07-22#topics-to-discuss
[2]: https://github.com/opencontainers/specs/pull/230/files#diff-38574c080d4e2eb38c49b86e6588ad98R50

Author: wking