Issue #2389345 by webchick: Add a block with a count of remaining critical issues to https://www.drupal.org/drupal-8.0/* sub-pages
Issue #2389345: Move block subject into standard place
Issue #2389345: Change block output from .tpl.php to render array
Issue #2389345: Merge branch '2389345-critical-count' into 7.x-3.x