Html flow / Layout refactor

I removed a lot of code that we had put in during the swipe navigation experiments.

Site looks the same, but the layout is simpler.

Thanks to this, it'll be simpler to iterate on it in the next few weeks.

- Removes old fronts ads code
- [fix] Top banner ads don't appear over the content when resizing the browser from desktop to mobile views
- Simplify layout by using natural HTML flow as much as possible instead of absolute positioning, enabling us to put anything on top of the header (like a top story as discussed)

@adamnfish you might want to test this one within an identity template, just in case.

![ ](http://1.bp.blogspot.com/-WyrmIaOMpzg/Ut_rvzHDlQI/AAAAAAABFZw/d5HWMzHHGgM/s1600/slow-motion.gif)