Extract `tagged_editions` table to a partial
Add filtering to topic pages
Fix failing ClassificationFeaturingsController test
Adding functional tests for filtering
Scenarios for filtering featured documents on topics
Make external statistics links clearer, mirroring the style used in search results
Un-foo/bar tests

Call me a grump, but I find the use of foo/bar in variable names and
values to be unhelpful; there is almost always a more meaningful name/
value that can be used. Also, we shouldn't use instance variables in the
tests where locals will do.
:with_topics trait is redundant if topic supplied
Filtered docs should be scoped to classication

When filtering documents on the topic/topical event featuring page, we
want returned documents to be only those that are actually tagged to the
topic/topical event in question.
Banner for closed organisations

Pivotal Tracker story: 66185062
We used to be able to mark an organisation as closed, and specify any superseding organisation.
We now can now specify the reason for closure of an organisation.
The green 'closed' banner now has more meaningful content about the closure of an organisation.
Fix external publication cucumber test

Previous test depended on template copy, refactor it A) pass and B) test what we now care about:
* There is a link to the external publication itself
* The link is also marked as rel=external, which will visually highlight the externalness to the user
* Ensure the full external URL is visible to the user, somewhere, to set an expectation of where they're going
Merge pull request #1463 from alphagov/external-statistics-link-styling

Make external statistics links clearer
Fix indentation to use spaces, not tabs
Adjusting column spacing to keep it consistent
Merge pull request #1453 from alphagov/filter-documents-to-feature-on-topics-pages

Filter documents to feature on topics pages
Consistent use of full stop

Up to now, the organisation status description text only had a full
stop if it contained more than one sentence.
Make helper responsible for returning safe string
Fix schema.rb
Combine closed and no_longer_exists traits

It doesn't make sense to have one without the other.
Ensure all closed orgs have a closed status

Otherwise those organisations will fail validation and also the
organisation_closed_govuk_status_description helper returns a blank
string for closed orgs that don't have a closed status.