tearing out MHCP_TCPIP.h

I do not like the idea of a lot of the details of TCPIP and wifi setup
taking place in a header file that is dominated by macros, so I am
moving the functionality of MHCP_TCPIP.h into my TCPIP framework.

I am also tearing apart that functionality and removing support for
anything that is not my wifi module.  I do not need those additional
checks in my code because there is no alternative hardware that I need
to support.
I think I'm done with the demo

I finished doing most of the cleanup, although I have a couple of
unanswered questions, such as why the pass phrase is marked as invalid
every time the TCPIP stack is serviced, but it works well.

Next step is a readme to describe the setup.
finished the readme

I finished the first draft of the readme.  I will now send it off to a
student colleague of mine to see if he can get it running without much
trouble.