replace unicode arrows

* ⇒, →, ←
* because we don't want to show them in documentation snippets and
  then it's complicated to avoid that when snippets are
  located in src/test/scala in individual modules
* dont replace object `→` in FSM.scala and PersistentFSM.scala

akka-distributed-data/src/test/scala/akka/cluster/ddata/LotsOfDataBot.scala

@@ -28,7 +28,7 @@ object LotsOfDataBot {
   }
 
   def startup(ports: Seq[String]): Unit = {
-    ports.foreach { port ⇒
+    ports.foreach { port =>
       // Override the configuration of the port
       val config = ConfigFactory.parseString("akka.remote.netty.tcp.port=" + port).
         withFallback(ConfigFactory.load(
@@ -87,9 +87,9 @@ class LotsOfDataBot extends Actor with ActorLogging {
   def receive = if (isPassive) passive else active
 
   def active: Receive = {
-    case Tick ⇒
+    case Tick =>
       val loop = if (count >= maxEntries) 1 else 100
-      for (_ ← 1 to loop) {
+      for (_ <- 1 to loop) {
         count += 1
         if (count % 10000 == 0)
           log.info("Reached {} entries", count)
@@ -111,24 +111,24 @@ class LotsOfDataBot extends Actor with ActorLogging {
         }
       }
 
-    case _: UpdateResponse[_] ⇒ // ignore
+    case _: UpdateResponse[_] => // ignore
 
-    case c @ Changed(ORSetKey(id)) ⇒
+    case c @ Changed(ORSetKey(id)) =>
       val ORSet(elements) = c.dataValue
       log.info("Current elements: {} -> {}", id, elements)
   }
 
   def passive: Receive = {
-    case Tick ⇒
+    case Tick =>
       if (!tickTask.isCancelled)
         replicator ! GetKeyIds
-    case GetKeyIdsResult(keys) ⇒
+    case GetKeyIdsResult(keys) =>
       if (keys.size >= maxEntries) {
         tickTask.cancel()
         val duration = (System.nanoTime() - startTime).nanos.toMillis
         log.info("It took {} ms to replicate {} entries", duration, keys.size)
       }
-    case c @ Changed(ORSetKey(id)) ⇒
+    case c @ Changed(ORSetKey(id)) =>
       val ORSet(elements) = c.dataValue
       log.info("Current elements: {} -> {}", id, elements)
   }