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/network/Messages/LatestMessages.java

@@ -289,8 +289,7 @@ public class LatestMessages extends Observable {
      * @return True if race, boat, and regatta have an xml message, false otherwise.
      */
     public boolean hasAllXMLMessages() {
-
-        if ((this.regattaXMLMessage == null) || (this.boatXMLMessage == null) || (this.raceXMLMessage == null)) {
+        if (this.regattaXMLMessage == null || this.boatXMLMessage == null || this.raceXMLMessage == null) {
             return false;
 
         } else {