Event sourcing

@ktoso
Also have a question regarding you reply here

especially with macros and the flexibility you get from actorReady so you can store it and register it for "when events arrive we'll call you"

I'm not sure where macros could be applied here, I guess exactly for func persist(event:) logic :thinking:
Also can you eloborate on actorReady function? There are no documentation and not sure how it can be used...