added classes for client and server state machine

- a client state machine consits out of a 'ClientState' (every state of the machine) and a 'ClientStateMachine' (every state, which consists out of states), the machine starts with the ClientAutomaton
- analog for server
- started to implement logic for the server, transition from 'Lobby' to 'GameState'

Projekte/mdga/model/src/main/java/pp.mdga/server/ServerSender.java

@@ -0,0 +1,7 @@
+package pp.mdga.server;
+
+import pp.mdga.message.server.ServerMessage;
+
+public interface ServerSender {
+    void send(int id, ServerMessage msg);
+}