refactored in getting the new instances for each handler
deleted class file replaced by UserEventHandler class
added UserEventHandler class replaced the LoginOrLogoutEventHandler
mocidifed to reflect the recent changes to UserEventHandler
renamed to MyUserEventHandler
added MyUserEventHandler class
fixed to reflect the changes to MyUserEventHandler class
modified to reflect the changes to the BaseManager class
made the listener into a final variable
added method to send an ErrorResponse to the sender
added a try/catch block in handling LeaveRoomRequest
called the sendErrorResponse method
modified the code that handles a user when he/she connects to the server