The client sends text messages to the server.
The client accepts the following commands from the keyboard:

1. _connect : this is to connect to the server by name declaration
2. _quit: the client disconnects from the server
3. _who: asks the server for a list of connected users

The server publish all text messages received from any client to all the connected clients.
The server accepts the following commands:
a. from a client or keyboard:
1. _who: same as _who in the client section above
b. from keyboard:
1. _kill : disconnect the client and inform all connected clients
2. _shutdown: stop the server
c. from client side:
1. _connect: the server inform all connected clients that a specific client has connected
2. _quit: the server inform all connected clients that a specific client has disconnected