!act,rem,clu #3549 Simplify and enhance routers

* Separate routing logic, to be usable stand alone, e.g. in actors
* Simplify RouterConfig, only a factory
* Move reading of config from Deployer to the RouterConfig
* Distiction between Pool and Group router types
* Remove usage of actorFor, use ActorSelection
* Management messages to add and remove routees
* Simplify the internals of RoutedActorCell & co
* Move resize specific code to separate RoutedActorCell subclass
* Change resizer api to only return capacity change
* Resizer only allowed together with Pool
* Re-implement all routers, and keep old api during deprecation phase
* Replace ClusterRouterConfig, deprecation
* Rewrite documentation
* Migration guide
* Also includes related ticket:
  +act #3087 Create nicer Props factories for RouterConfig

akka-docs/rst/java/code/docs/jrouting/RedundancyGroup.java

@@ -0,0 +1,58 @@
+/**
+ * Copyright (C) 2009-2013 Typesafe Inc. <http://www.typesafe.com>
+ */
+package docs.jrouting;
+
+//#group
+import java.util.List;
+
+import scala.Option;
+import scala.collection.immutable.Iterable;
+import akka.actor.ActorContext;
+import akka.actor.ActorPath;
+import akka.actor.ActorSystem;
+import akka.actor.Props;
+import akka.dispatch.Dispatchers;
+import akka.routing.Group;
+import akka.routing.Routee;
+import akka.routing.Router;
+import akka.routing.RouterActor;
+import akka.routing.RouterConfig;
+import akka.routing.RoutingLogic;
+
+import com.typesafe.config.Config;
+
+import akka.routing.GroupBase;
+import static docs.jrouting.CustomRouterDocTest.RedundancyRoutingLogic;
+
+public class RedundancyGroup extends GroupBase {
+  private final List<String> paths;
+  private final int nbrCopies;
+  
+  public RedundancyGroup(List<String> paths, int nbrCopies) {
+    this.paths = paths;
+    this.nbrCopies = nbrCopies;
+  }
+
+  public RedundancyGroup(Config config) {
+    this(config.getStringList("routees.paths"),
+      config.getInt("nbr-copies"));
+  }
+  
+  @Override
+  public java.lang.Iterable<String> getPaths() {
+    return paths;
+  }
+
+  @Override
+  public Router createRouter(ActorSystem system) {
+    return new Router(new RedundancyRoutingLogic(nbrCopies));
+  }
+
+  @Override 
+  public String routerDispatcher() {
+    return Dispatchers.DefaultDispatcherId();
+  }
+ 
+}
+//#group