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.
If you want to see how I was doing these kind of assertions back when I was writing selenium tests for MAGFest, check this out:
https://github.com/magfest/ubersystem/blob/b5afab24b63bfe91ebc700be425e2f06a0294718/tests/browser.py

Like I said, I'm ambivalent about doing selenium at this point in time, but if you do decide to go this route, there's some good stuff there to check out.