Added tell supervisor action to make system init work

Fixes #16 (closed) by introducing a new tell supervisor action, that is sent additionally to the ActionJoinAnswer message. If the answering node does not know the supervisor yet, it will postpone the "tell supervisor" action until it does know one. That way, we are able to spawn large amounts of wallets

src/main/java/fucoin/actions/join/ActionJoin.java

@@ -14,8 +14,14 @@ public class ActionJoin extends ClientAction {
     protected void onAction(ActorRef sender, ActorRef self, UntypedActorContext context, AbstractWallet node) {
 
         // send the joined node all known neighbours from node and a reference to the supervisor
-        ActionJoinAnswer aja = new ActionJoinAnswer(node.resolveSuperVisorActor());
+        ActionJoinAnswer aja = new ActionJoinAnswer();
         aja.someNeighbors.putAll(node.getKnownNeighbors());
         sender.tell(aja, self);
+
+        if (node.getRemoteSuperVisorActor() == null) {
+            node.deferSendOfSuperVisorActor(sender);
+        } else {
+            sender.tell(new ActionTellSupervisor(node.getRemoteSuperVisorActor()), self);
+        }
     }
 }