Chat applications
There are 3 sets of files here -
1. A Port Scanner that simply scans and lists the port numbers within an entered range that are currently idle
2. TCPClient and TCPServer are for a basic one way communication between a client and server
             The client sends something to the server and the server simply echoes it back
3. MultiThreadChatClient and MultiThreadChatServerSync are for an online chat application
     There are maxClient number of clients connected to the server and any client can send messages to any other client via the server. Also, if needed, the client can send a message specifcally to another client, i.e. a private message and thus this message would be visible only to that client. Otherwise, normal messages are broadcasted to all the other clients connected to the server.