Issue Make twig the default engine once all modules templates are converted from .tpl.php to .html.twig [#1806478].
Issue Convert views/templates/views-exposed-form.tpl.php to twig [#1843740].
Issue Convert views/templates/views-more.tpl.php to twig [#1843742].
Issue Convert views/templates/views-view.tpl.php to twig  [#1843744].
Issue Convert views/templates/views-view-field.tpl.php to Twig  [#1843746].
Issue Convert views/templates/views-view-fields.tpl.php to twig [#1843748].
Issue Convert views/templates/views-view-grid.tpl.php to twig [#1843750].
Issue Convert views/templates/views-view-grouping.tpl.php to twig [#1843752].
Issue Convert views/templates/views-view-list.tpl.php to twig [#1843754].
Issue [READY] Convert views/templates/views-view-row-rss.tpl.php to twig [#1843758].
Issue [READY] Convert views/templates/views-view-rss.tpl.php to twig [#1843760].
Issue Convert views/templates/views-view-summary.tpl.php to twig [#1843762].
Issue Convert views/templates/views-view-summary-unformatted.tpl.php to twig [#1843764].
Issue Convert views/templates/views-view-table.tpl.php to twig [#1843766].
Issue Convert views/templates/views-view-unformatted.tpl.php to twig [#1843770].
Issue [READY] Convert views/views_ui/templates/views-ui-display-tab-bucket.tpl.php to Twig [#1843772].
Issue [READY] Convert views/views_ui/templates/views-ui-display-tab-setting.tpl.php to Twig [#1843774].
Issue aggregator.module - Convert PHPTemplate templates to Twig [#1896060].
Issue block.module - Convert PHPTemplate templates to Twig [#1898034].
Issue comment.module - Convert PHPTemplate templates to Twig [#1898054].