Added functionality for more than one visualiser to connect to the mock.

- more than one visualiser can now connect to the mock.
- Created class ConnectionAcceptor that will accept and allocate to each socket
- Issue of sockets connecting after the race starts then disconnecting will use a socket slot.
#story[1010]

racevisionGame/src/main/java/visualiser/model/RaceConnection.java

@@ -33,6 +33,10 @@ public class RaceConnection {
         try (Socket s = new Socket()){
             s.connect(i, 750);//TODO this should be at least a second or two, once moved to its own thread
             status.set("Ready");
+            s.shutdownInput();
+            s.shutdownOutput();
+            s.close();
+            System.out.println(String.valueOf(s.isClosed()));
             return true;
         } catch (IOException e) {}