[html-formfu] client-side constraints

[Carl Franks]

If anyone's interested, I've updated my demo of client-side filters
and constraints, so that it no longer uses the Dojo library.

It now only uses standard JavaScript.
It no longer requires a script tag within the head tags - all code is
now within the form tags.
I've also moved some repeated code out into functions, to simplify things.
I've also fixed a couple of bugs with the onsubmit handler.

The html page is now in svn, in
/trunk/HTML-FormFu/examples/client-side-constraint/

This is still just proof-of-concept. I'll next be working on making
FormFu actually able to generate it.

Carl