wrap up local routing

- pull some more generic stuff out of the individual routers, add
  factories which take only target lists
- add router parsing to Deployer, removing everything which is not
  strictly related to local scope, which left only few things, so move
  them to Deployer.scala and delete DeploymentConfig
- fix ConfiguredLocalRoutingSpec to use the new configuration mechanism
  and verify that configuration overrides code
- fix DeployerSpec by using (mostly) correct lookup paths and removing
  everything which was not local
- change config file layout, removing everything which is not local from
  akka-actor/.../reference.conf, putting the remote stuff into the
  akka-remote/.../reference.conf (unused as of yet); adapt comments
  according to changed functionality

akka-actor-tests/src/test/scala/akka/routing/RoutingSpec.scala

@@ -3,7 +3,6 @@ package akka.routing
 import java.util.concurrent.atomic.AtomicInteger
 import akka.actor._
 import collection.mutable.LinkedList
-import akka.routing.Routing.Broadcast
 import java.util.concurrent.{ CountDownLatch, TimeUnit }
 import akka.testkit._