more cleanup

I've now got things to the point where RMI should be a piece of cake. The Portal interface now has a single method, newChannel, which returns an instance of the Channel interface. And that in turn has two methods, initialRequest and processRequest, which provide access to the server.

There is also a new DirectChannel class in the directclient package in the ark project which extends the channel interface.

The UI class also is now a complete class, rather than being abstract. There will no doubt be multiple specialized UI classes for different client interfaces, but UI provides the basics.

Hopefully all these changes will help make the top-level architecture easier to understand.

I still need to clean up the Swing client, at least to the point it was before, and then do a release. After that I need to spend some time on the Swing client. Then I'd like to implement RMI.

Bill