java.net.Socket implementation

I created a basic clean-room implementation of java.net.Socket class (and improved some connected additional classes).

The implementation doesn't contain all the methods of the original one, but it is sufficient to connect to a remote server and send/receive data.

I tested it by connecting to an HTTP-server under Windows 7 and OS X 10.8. It works satisfactory.

As for now only TCP-socket is implemented for IPv4 addresses.

If you accept this pull-request I'll try to resolve all possible bugs connected to it. And in addition I'm going to implement ServerSocket soon.