=act #15102 No serialization needed for EventStreamUnsubscriber

* The problem was that akka://all-systems/StandardOutLogger ref was
  passed during system shutdown
* Add special serialization of StandardOutLogger, and Nobody
Merge pull request #15115 from akka/wip-15102-all-systems-noise-patriknw

=act #15102 No serialization needed for EventStreamUnsubscriber
=pro #15031 separate sbt build file for every module