Store API areas in the Rails cache

... rather than memoizing them as an ivar; ensures that they can be
cleared by hitting the "Clear cache" button in the admin section.
Redirect after setting a new locale

If the "locale" parameter is present, redirect back to the current page,
removing the param.

Closes #1800.
Changed labels of new countries from Draft to New; re-ordered the countries.
Merge pull request #1801 from quintel/remove_draft_label

Changed labels of new countries from Draft to New; re-ordered the countries.