Modified Default.htm to work with "File://" protocol

Previously loading the Default.htm file in the browser using a URL that started with "File://" would cause JQuery not to load. I changed the reference to the JQuery file to an explicit "http://" protocol to fix this problem. This allows the user to run the app locally without needing a development web server.

The downside is of course the user may get an "insecure content warning" if they load Default.htm over https. However, I believe this is a worthwhile tradeoff.