Implemented the log on and log off systems

This is a pretty straight forward port of the old version, including the
incredibly hacky server list. But I just need to remember that this is a
prototype.

client/client_application.hpp

@@ -51,6 +51,7 @@ private:
 
 	ConfigUtility config;
 	UDPNetworkUtility network;
+	int clientIndex = -1; //replace with a struct?
 };
 
 #endif