[cells-devel] deep-cells test and Cells 3 demo

[Ken Tilton]

Writing the doc got scary, and I remembered that anyway I want to lean
towards literate programming for doc, so I added more to the comments
in integrity.lisp and created a test suit entry that shows a whole lot
going on, including an ephemeral initialized to non-nil, and a client
sort to get observer actions to come out in the right order.

If anyone has questions, just ask. If it seems best, I'll respond by
extending the code comments and pointing you to that.

kt