Documentation updates and correct handling of TCP connections.

While trying to use a TCP connection to a remote docker server, I ran into a problem where the connection would always use Sockets.  This is because there wasn't a way to disable sockets and use TCP connection information.  Then when I added the ability to disable sockets, the TCP connection information was hardcoded into the Endpoint class.

These changes add the ability to disable sockets when using TCP and to correctly populate the TCP info into the request.  I've also updated the documentation for this new functionality.

I also added documentation for the `images.list` method which I found useful but undocumented.