Cleanup.
Implement in-memory timeout for process manager.
Logging added to process initiator.
Support () to mean ignore the event in the aggregate.
Add EventData apply/unapply to Aggregate.
Change aggregate.applyEvent to be a PartialFunction.
ProcessManager.handle now returns a tuple instead of a trait. This is easier to use in implementations.
Allow aggregate.Event to match EventData also.
Add order/payment model for tests.