Data packet:
struct CB_Data_Packet {
  int channel;        4 bytes
  int command;        4 bytes
  char handle[20];    20 bytes
  char message[100];  100 bytes
};

Commands:

1. CB_ON
   Sets up data on server and sends welcome message
2. CB_OFF
   Closes socket and removes client data from server
3. SET_CHAN
   Sets the client's channel to the data contained in the channel field.
4. WHO_CHAN
   Creates a message containing the handles of everyone subscribed to the client's channel and sends it back to the requesting client.
5. WHO_ALL
   Same as above, but for all channels **not implemented yet**
6. SVR_STATS
   Send some stats on the server to a client **not implemented yet**
7. SEND_MESSAGE
   Broadcasts the message contained in the message field to all clients