Introduce parental supervision, BUT TESTS ARE STILL FAILING

- every actor is now supervised, where the root of the tree is
  app.guardian, which has its supervisor field set to a special ActorRef
  obtained from provider.theOneWhoWalksTheBubblesOfSpaceTime (this name
  is meant to indicate that this ref is outside of the universe, cf.
  Michio Kaku)
- changed all tests to obtain specially supervised children (i.e. not
  top-level) via (supervisor ? Props).as[ActorRef].get
- add private[akka] ScalaActorRef.sendSystemMessage for sending
  Supervise()
- everything routing or remote is broken wrt. supervision, as that was
  not “properly” implemented to begin with, will be tackled after
  app/supervision/eventbus/AkkaSpec are stabilized enough

akka-remote/src/main/scala/akka/serialization/SerializationProtocol.scala

@@ -201,15 +201,14 @@ class ActorSerialization(val app: AkkaApplication, remote: RemoteSupport) {
     }
 
     val props = Props(creator = factory,
-      timeout = if (protocol.hasTimeout) protocol.getTimeout else app.AkkaConfig.ActorTimeout,
-      supervisor = storedSupervisor //TODO what dispatcher should it use?
+      timeout = if (protocol.hasTimeout) protocol.getTimeout else app.AkkaConfig.ActorTimeout //TODO what dispatcher should it use?
       //TODO what faultHandler should it use?
-      //
       )
 
     val receiveTimeout = if (protocol.hasReceiveTimeout) Some(protocol.getReceiveTimeout) else None //TODO FIXME, I'm expensive and slow
 
-    val ar = new LocalActorRef(app, props, protocol.getAddress, false, actorUuid, receiveTimeout, storedHotswap)
+    // FIXME: what to do if storedSupervisor is empty?
+    val ar = new LocalActorRef(app, props, storedSupervisor getOrElse app.guardian, protocol.getAddress, false, actorUuid, receiveTimeout, storedHotswap)
 
     //Deserialize messages
     {