remove references to Remote* from akka-actor

- moved RemoteInterface.scala into akka-remote, not needed anymore since
  the plugin is loaded as ActorRefProvider now
- removed some old unused imports
- split out remote aspects from Deployer & DeployerSpec into
  RemoteDeployer & RemoteDeployerSpec (the latter in akka-remote)
- created a ticket for cleaning up the rest, mostly remove all
  occurrences of “remote” and “cluster” from akka-actor in this way

All of this was triggered by wanting to:
- change the signature of RemoteSupport.send to require a RemoteActorRef
  recipient

akka-remote/src/main/scala/akka/remote/Gossiper.scala

@@ -161,7 +161,7 @@ class Gossiper(remote: Remote) {
           node ← oldAvailableNodes
           if connectionManager.connectionFor(node).isEmpty
         } {
-          val connectionFactory = () ⇒ RemoteActorRef(remote.system.provider, remote.server, gossipingNode, remote.remoteDaemon.path, None)
+          val connectionFactory = () ⇒ new RemoteActorRef(remote.system.provider, remote.server, RootActorPath(gossipingNode) / remote.remoteDaemon.path.elements, None)
           connectionManager.putIfAbsent(node, connectionFactory) // create a new remote connection to the new node
           oldState.nodeMembershipChangeListeners foreach (_ nodeConnected node) // notify listeners about the new nodes
         }