WIP Selenium testing

couple changes:
1) made public facing default landing page (index.html) extend base-admin.html, which includes base.html. important because:

2) added dummy DIV "bottomAnchor" on the base.html page that selenium can look for to make sure the page is fully loaded

3) added some very WIP first pass selenium tests which run Firefox and click on things.  My goal is to have the attendee prereg form be covered pretty well with some selenium testing as a first start for getting some functional testing up.
So I see what you're doing here, but this actually isn't necessary.  When you call ``WebDriver.get()`` it blocks until the entire page is loaded.  This is NOT the same as saying that the page is ready to be interacted with, because you might need to wait for some Javascript to have run, for event handlers to be added, etc.  I'll leave some comments down below about some better ways to do this.