Issue #2134909 by Xano, Wim Leers: Clean up editor.module to match coding standards.

core/modules/editor/css/editor.css

core/modules/editor/js/editor.admin.js

core/modules/editor/lib/Drupal/editor/EditorController.php

core/modules/editor/lib/Drupal/editor/EditorInterface.php

core/modules/editor/lib/Drupal/editor/Plugin/EditorBase.php

...editor/lib/Drupal/editor/Plugin/EditorPluginInterface.php

...or/lib/Drupal/editor/Tests/EditIntegrationLoadingTest.php

...es/editor/lib/Drupal/editor/Tests/EditIntegrationTest.php

...odules/editor/lib/Drupal/editor/Tests/EditorAdminTest.php

...es/editor/lib/Drupal/editor/Tests/EditorFileUsageTest.php

...ules/editor/lib/Drupal/editor/Tests/EditorLoadingTest.php

...ules/editor/lib/Drupal/editor/Tests/EditorManagerTest.php

...es/lib/Drupal/editor_test/Plugin/Editor/UnicornEditor.php