Fix frontend statistics announcement bug

The most recent change note should always be displayed regardless of whether it
was the most recent change or not.
Remove unnecessary indirection

The use of a separate presenter here on the statistics_announcements#show action
is unnecessary indirection as pretty much all the methods required in the view
are already present on the model. It also makes it more likely that bugs like
the one fixed by the previous commit will occur.
Enable Estonian translations
Import Estonian translations
Prevent test from failing due to timing issue

The test here is not concerned with the order these editions are returned in,
just the fact that the correct ones are returned. By using assert_same_elements,
we don't have to worry about the nondeterministic order they may be returned in
because they are created at the same time (time is frozen in the test suite).
Merge pull request #1819 from alphagov/fix-nondeterministic-test-failure

Prevent test from failing due to timing issue
Remove exempt orgs thumbnails

• Remove unnecessary code from not_live page
• Remove nested css for that section on for exempt orgs
• Update styles for adjacent elements to fix layout
• Remove unsed code from helper
• Remove rake task for generating thumbnails

https://www.agileplannerapp.com/boards/105200/cards/5218
Removed unused screenshots
Remove email curation queue feature

www.agileplannerapp.com/boards/173808/cards/6034

As a DCLG editor
I want documents tagged to "relevant to local government"
  to not be held in a curation queue
So that I no longer have to curate email alerts for
  local government users

instead these notifications will be sent to govdelivery
as soon as documents are published.
Data migration to flush email curation queue

www.agileplannerapp.com/boards/173808/cards/6034

before we remove the email curation queue feature
we need to send notifications to subscribers for
any pending items in that queue. this migration
takes care of that.
Merge pull request #1821 from alphagov/remove-email-curation-queue

Remove email curation queue
Change ISCO org screenshot

ISC currently don't have an accurate screenshot (it's of the Security
Services website) which potentially compromises their image as
impartial. They have supplied a new screenshot image in
https://govuk.zendesk.com/agent/tickets/856092 and this updates the
image to the one they supplied (scaled/cropped to 287x215 as per the
other images in this folder)
Merge pull request #1822 from alphagov/change-isc-screenshot

Change ISCO org screenshot
Revert "Change ISCO org screenshot"
Merge pull request #1823 from alphagov/revert-1822-change-isc-screenshot

Revert "Change ISCO org screenshot"
Merge pull request #1820 from alphagov/remove-external-org-thunmbnail

PO accepted according to @russelthorn
Merge pull request #1818 from alphagov/estonian-translations

Enable Estonian translations
Merge pull request #1815 from alphagov/fix-frontend-statistics-announcements-bug

Fix frontend statistics announcements bug