fixed bug with seriliazation of Board, now sending playerdata seperate from teh board

Projekte/mdga/client/src/main/java/pp/mdga/client/server/MdgaServer.java

@@ -144,6 +144,8 @@ private void initializeSerializables() {
         Serializer.registerClass(StartNode.class);
         Serializer.registerClass(PlayerData.class);
         Serializer.registerClass(HomeNode.class);
+        Serializer.registerClass(PlayerDataMessage.class);
+        Serializer.registerClass(StartBriefingMessage.class);
     }
 
     private void registerListeners() {