Use $.animate on html instead of body so viewport is scrolled to top on navigation

This looked like intended functionality that wasn't working for me (OSX, Chrome) but seemed like a solid idea. This has some funkiness to it, however, as it seems like `animateContent()` is invoked more than once on page load. I haven't been able to look into that yet though. The end result is a bit of flickering... may not be an improvement. What do you think?