Note 1: Username cannot be empty string (to prevent attacks), or cannot contain any whitespaces
Note 2: Users will not see their own client names under Users tab (while the other clients can!), to prevent them from sending direct messages to themselves
Note 1: Users will not see their own client names under Users tab (while the other clients can!), to prevent them from sending direct messages to themselves
Note 2: Users can gracefully disconnect from the ChatRoom by typing "/exit" to the broadcast chat (will update this commit once I resolve how to disconnect a client after shutting down from the Windows app or CTRL-C on client console)
