ProcessManagerActor now uses PubSub.
Add at-least-once to event publishing in aggregate actor.
Implement id serialization.
Implement process termination.
Simplify handleEvent.
Add toString to topic.
Fix line-endings (no code change).
Implement subscribe and unsubscribe in process manager.
Code cleanup.
Add subscription manager for PubSub.
Add reliability to the subscriptions.
rename impl.actor to infrastructure.akka.