AggregateRoot renamed to AggregateRootActor
Removing Akka awareness from domain part 1

- AggregateRoot and its direct subclasses are not depending from Akka
- AggregateRootActor introduced to encapsulate Akka connected behaviors.
Removing Akka awareness from domain part 2

- CommandAdapter (which replaces AggregateManager in a domain scope ) and its direct subclasses are not depending from Akka
- AggregateManager encapsulate Akka connected behaviors.
- Some file names are not change yet
Removing Akka awareness from domain part 2

- files renaming (wanna be sure that file history will be tracked by git)
Merge remote-tracking branch 'origin/attempt_to_improve_design' into attempt_to_improve_design

Conflicts:
	src/main/scala/io/scalac/seed/domain/AggregateRootActor.scala
	src/main/scala/io/scalac/seed/domain/UserAggregate.scala
	src/main/scala/io/scalac/seed/domain/VehicleAggregate.scala
	src/main/scala/io/scalac/seed/service/AggregateManager.scala