https compatibility

[ianshward]

I'm in the process of making sure all of www.mapbox.com/* will work well under https, which means updating non-https resources to https wherever possible. I found a couple of references in this repo which do not have https counterparts:

• All of the problematic resources I found in use only on http://www.mapbox.com/foursquare-store-locator/frame.html which has other problems, like 404's on several of the problematic resources over http, which makes me wonder whether this frame.html page is still in use.