More comprehensive reporting of termination reasons

[bgrant0607]

Docker reports State.Running, State.Paused, State.ExitCode (negative for signals IIRC), and State.FinishedAt. It would be useful to collect even more termination reason information, such as:

• stop/restart operations, with client-provided reason, such as "cancel", "reload", "resize", "move", "host_update"
• liveness probe failures (see Add extended health checking of pods/containers #66)
• other identifiable failure reasons: OOM, container creation error, docker crash, machine crash, reboot, lost/ghost

[bgrant0607]

We also need to think about how to report this information to clients if pods are deleted upon termination. Clients will want to watch for termination and receive the reason and other details. Logs are not sufficient for programmatic use.

[dchen1107]

#1569 was merged. All available termination reasons are propagated to apiserver through ContainerStatus. Several docker issues were filed, and some of them already handled by docker. Several ones including oom are in @rjnagal's hand already. Once those docker issues are addressed properly, the related reasons are going to propagated automatically without further changes.

Client initialized reason will be handled separately. Close this one.