Update Foursquare and Yelp screenshots

I don't think I need to both with two views for their mobile apps, so consolidating.

Also, switching query terms from "Salad" to "Japanese" to match examples later.

Note that I had to git filter-branch out the old Foursquare photos, since they had photos of my friends. These have been edited to have Facebox.io avatars and made-up names :)