AKKA Actor snippets

# AKKA Actor snippets

## [scala][akka] avoid sender mixing (using pattern match guard)

```         
         def receive = {
            case x if sender == child1 => do sth
            case x if sender == child2 => do sth else
            case x                    => child forward x
         }

```          

## [scala][akka] actor selection to actor ref 

From: http://stackoverflow.com/questions/10549026/in-akka-how-do-i-know-when-an-actor-is-ready-to-use-after-having-been-registere

```
implicit val timeout = Timeout(5, TimeUnit.SECONDS)
val selection = system.actorSelection("/user/myActor")
val actor = Await.result(selection.resolveOne(), timeout.duration)
```

## [scala][akka] I got dead letter and sender changes
* http://stackoverflow.com/questions/20650007/sender-becomes-actorakka-main-deadletters

## [Scala][akka] chain messagine A->B->C
* Using forward instead of tell (http://stackoverflow.com/questions/25115547/difference-between-forward-and-tell-in-akka-actors)