Reworked status page

Please see demos:

- http://sandbox.mikepurvis.com/build_status/hydro.html
- http://sandbox.mikepurvis.com/build_status/groovy.html?q=blue&s=5

Works great on Chrome and Safari, okay but a bit sluggish on Firefox—probably no hope of IE support. If it's felt to be necessary, I can put in detection to at least produce a popup warning.

Highlights are quicker loading, filtering, sorting, replaceState url, and way, way more compact page size.

A lot of small features have had to be partially or fully re-implemented, especially stuff which got moved from the Python generator to JavaScript—for regular users of this page, please give the demos a quick shot and let me know if any functionality you rely on has been lost. Things which have been lost (but could be restored upon request) include: separate diff1/diff2/etc searching, sorting on the version block columns, and possibly more which I wasn't aware of.

There's also a ton of remaining cleanup which is possible in the Python generator. I haven't bothered to remove all of the stuff which is now no longer in use; as much as possible, I stayed focused on the front-end business of JS and CSS.

This PR addresses issue #149.