Overlay topology

This merge requests adds the presented overlay topology creation. This way, one does not have to modify the Distributed Commit to obtain a overlay network that is used by the implemented algorithms, which should not work on a fully connected network. The topologies are defined via Gephi.

src/main/java/fucoin/actions/control/ActionAddOverlayNeighbours.java

+package fucoin.actions.control;
+
+import akka.actor.ActorRef;
+import akka.actor.UntypedActorContext;
+import fucoin.actions.ClientAction;
+import fucoin.wallet.AbstractWallet;
+
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * @author davidbohn
+ */
+public class ActionAddOverlayNeighbours extends ClientAction {
+
+    protected List<ActorRef> neighbours;
+
+    public ActionAddOverlayNeighbours(List<ActorRef> neighbours) {
+        this.neighbours = neighbours;
+    }
+
+    @Override
+    protected void onAction(ActorRef sender, ActorRef self, UntypedActorContext context, AbstractWallet abstractNode) {
+        neighbours.stream().forEach(abstractNode::addOverlayNeighbour);
+    }
+}