Enhanced-UI for non-English editions

Make the UX a bit nicer with a sprinkling of JavaScript. We hide the
locale select fields by default, revealing them when the user clicks
a reasonably anonymous link. Non-JS users see the fields by default,
so everything should just work.
Locale returns all right-to-left languages
Handle RTL languages for non-English editions

We apply the appropriate classes to the form if a user selects a
right-to-left language for a non-English edition.
Correctly render right-to-left editions and forms

This makes sure that right-to-left non-English editions are rendered
appropriately when viewed in admin. It also ensures that the edit form
fields are right-to-left when appropriate. Note that I have only
updated the form partials that are directly used for world location
news articles. If non-English support is added to other edition
types, the appropriate form field partials will need updating
accordingly. As a bonus, I've updated admin preview of
translations to account for right-to-left languages.