Translated local news for non english speaking local people

Allow world location news articles to be translated.  Simple enough; make ``WorldLocationNewsArticle#translatable?`` return ``true`` and set ``localized: true`` on the public facing routes.

In passing added unit tests for world location news articles and corrected the search_format_types.  Things that should have been in #307.

https://www.pivotaltracker.com/story/show/44946239