Non-functional feature file for location news articles
Associate editions with worldwide priorities

Only the back-end plumbing so far
Wrap priority selector in conditional

I expect we'll not want to link *all* news items to priorities, so
prepare for this day with a conditional.
Add a bunch of features
Introduce Newsesque and WorldLocationNewsArticle

It sits between Announcement and NewsArticle to provide a "base" class for news-type announcements, which is what the new WorldLocationNewsArticle is.
Fix some more features
Add (broken) admin functionality for world location news articles
Remove news type
Add display_type_key for new type
Add steps for world location news articles and reword features
Add WorldLocationNewsArticle to admin routes
Don't validate organisations for world location news
Add can_be_related_to_organisations? method

World Location News doesn't have organisation relationships, so make
this optional in the model and the form.

Unfortunately this is inherited all the way up in Edition, so we have to
do it in a slightly ugly way.
Route for World Location News pages
Make sure Newsesque can be STI'd
Avoid "Edit" link collision: Rename "Eddie Editor" to "Eddie Depteditor"

In our cucumber if we're logged in as an editor and we click_link "Edit" the first link on the page with the text "Edit" is our name and this takes us to the wrong place.  It's easier to rename our editor than it is to introduce extra styling just to help the tests target the document nav actions.
Provide frontend controller for world location news articles
Add a latest feed to worldwide priority pages

This is populated by the most recent related world location news articles.
filter_form partial now takes a filters array instead of many booleans

This is based on something @tomafro suggested, and it makes the API for using this partial a bit nicer.
Add concrete_descendants_Search_format_types to Edition

This allows us to get all the subclasses that are actually document types (e.g. we get the search format type of NewsArticle, but not from Newsesque or Announcement).