Hide ads on rotate

After a bit of a play I don't really think it's very nice to reload all the adverts on resize.

For example, when a taller advert comes along the viewport is jolted down. If you accidentally rotate your device and back again then you trigger a double load, which makes everything a bit sluggish.

So I'm just hiding them for now.

Depends on #2278, so diff against that for my local changes.

/cc @phamann @ironsidevsquincy