introduce AkkaApplication

- remove global Config
- pull everything which depended on it into new AkkaApplication
- leave EventHandler alone for the moment: that evil sucker gets his
  very own AkkaApplication("akka-reference.conf") until we have settled
  on an acceptable logging API without globals
- make akka-actor and akka-testkit compile
- TestKit uses implicit AkkaApplication passing for maximum convenience
- Actor object nearly completely removed, actor creation possible via
  ActorRefFactory interface which is implemented by AkkaApplication and
  ActorContext
- serialization of ActorRef is probably broken, and so is the reflective
  RemoteSupport (now needs AkkaApplication constructor arg)
- everything else is still broken, including akka-actor-tests, so this
  is of course all not runtime-tested

akka-actor/src/main/scala/akka/actor/Scheduler.scala

@@ -28,16 +28,12 @@ object Scheduler {
   private[akka] val service = Executors.newSingleThreadScheduledExecutor(SchedulerThreadFactory)
 
   private def createSendRunnable(receiver: ActorRef, message: Any, throwWhenReceiverExpired: Boolean): Runnable = {
-    receiver match {
-      case local: LocalActorRef ⇒
-        val uuid = local.uuid
-        new Runnable {
-          def run = Actor.registry.local.actorFor(uuid) match {
-            case None        ⇒ if (throwWhenReceiverExpired) throw new RuntimeException("Receiver not found, unregistered")
-            case Some(actor) ⇒ actor ! message
-          }
-        }
-      case other ⇒ new Runnable { def run = other ! message }
+    new Runnable {
+      def run =
+        if (receiver.isShutdown && throwWhenReceiverExpired)
+          throw new RuntimeException("Receiver not found, unregistered")
+        else
+          receiver ! message
     }
   }