Modules and Classes:

- Split out the connecting and forwarding logic into the proxy_connector file
- Made two new classes:
    - ProxyConnector: handles incoming new request
                      There is one of these per proxy server.

    - ProxyRequestor: handles each request from server and forward back
                      to user.

                      There is one of these per client connection.

This was also an exercise in building up closures from classes and their
methods. See the method() function.