Fixing merge with 8.x

core/includes/bootstrap.inc

core/includes/common.inc

core/includes/form.inc

core/modules/aggregator/aggregator.admin.inc

core/modules/aggregator/aggregator.info

core/modules/aggregator/aggregator.test

...es/aggregator/lib/Drupal/aggregator/Tests/AddFeedTest.php

...b/Drupal/aggregator/Tests/AggregatorConfigurationTest.php

...egator/lib/Drupal/aggregator/Tests/AggregatorCronTest.php

...r/lib/Drupal/aggregator/Tests/AggregatorRenderingTest.php

...egator/lib/Drupal/aggregator/Tests/AggregatorTestBase.php

...or/lib/Drupal/aggregator/Tests/CategorizeFeedItemTest.php

...egator/lib/Drupal/aggregator/Tests/CategorizeFeedTest.php

...aggregator/lib/Drupal/aggregator/Tests/FeedParserTest.php

...aggregator/lib/Drupal/aggregator/Tests/ImportOpmlTest.php

...egator/lib/Drupal/aggregator/Tests/RemoveFeedItemTest.php

...aggregator/lib/Drupal/aggregator/Tests/RemoveFeedTest.php

...egator/lib/Drupal/aggregator/Tests/UpdateFeedItemTest.php

...aggregator/lib/Drupal/aggregator/Tests/UpdateFeedTest.php

core/modules/block/block.info