Refactor syndicated to include gateway start-stop logic in syndicate.observer.startstop.
This package not only gives syndicated the ability to instantiate, uninstantiate, start, stop,
and check the runtime status of individual gateways, but also allows it to synchronize a set of
volumes' gateways with the observer.  That is, syndicate.observer.startstop has higher-order
methods for bringing a nodes' gateways inline with the observer's model of what gateway should
be running where, in order to bind the Volume to the slice.