The `paused` state is used as an operator safety mechanism, so that they can
debug a deployment or halt one that's causing a wider failure. By using the
`paused` state as the first state of a multiregion deployment, we risked
resuming an intentionally operator-paused deployment because of activity in a
peer region.
This changeset replaces the use of the `paused` state with a `pending` state,
and provides a `Deployment.Run` internal RPC to replace the use of the
`Deployment.Pause` (resume) RPC we were using in `deploymentwatcher`.
* `nextRegion` should take status parameter
* thread Deployment/Job RPCs thru `nextRegion`
* add `nextRegion` calls to `deploymentwatcher`
* use a better description for paused for peer