Issue #1541684 by Rob Loach, aspilicious: Convert PagerDefault db extender to PSR-0.

core/includes/database.inc

core/includes/pager.inc

core/lib/Drupal/Core/Database/Query/ExtendableInterface.php

core/lib/Drupal/Core/Database/Query/PagerSelectExtender.php

core/modules/aggregator/aggregator.pages.inc

core/modules/comment/comment.admin.inc

core/modules/comment/comment.module

core/modules/dblog/dblog.admin.inc

core/modules/entity/lib/Drupal/entity/EntityFieldQuery.php

core/modules/forum/forum.module

core/modules/locale/locale.pages.inc

core/modules/node/node.admin.inc

core/modules/node/node.module

core/modules/path/path.admin.inc

core/modules/poll/poll.pages.inc

core/modules/search/search.api.php

core/modules/statistics/statistics.admin.inc

core/modules/statistics/statistics.pages.inc

core/modules/system/system.admin.inc

core/modules/system/tests/database.test