Merged issue-1806478 into develop.

* issue-1806478:
  Issue Make twig the default engine once all modules templates are converted from .tpl.php to .html.twig [#1806478].
Merged issue-1843740 into develop.

* issue-1843740:
  Issue [READY] Convert views/templates/views-exposed-form.tpl.php to twig [#1843740].
Merged issue-1843742 into develop.

* issue-1843742:
  Issue [READY] Convert views/templates/views-more.tpl.php to twig [#1843742].
Merged issue-1843744 into develop.

* issue-1843744:
  Issue [READY] Convert views/templates/views-view.tpl.php to twig  [#1843744].
Merged issue-1843746 into develop.

* issue-1843746:
  Issue [READY] Convert views/templates/views-view-field.tpl.php to Twig  [#1843746].
Merged issue-1843748 into develop.

* issue-1843748:
  Issue Convert views/templates/views-view-fields.tpl.php to twig [#1843748].
Merged issue-1843750 into develop.

* issue-1843750:
  Issue [READY] Convert views/templates/views-view-grid.tpl.php to twig [#1843750].
Merged issue-1843754 into develop.

* issue-1843754:
  Issue [READY] Convert views/templates/views-view-list.tpl.php to twig [#1843754].
Merged issue-1843758 into develop.

* issue-1843758:
  Issue [READY] Convert views/templates/views-view-row-rss.tpl.php to twig [#1843758].
Merged issue-1843760 into develop.

* issue-1843760:
  Issue [READY] Convert views/templates/views-view-rss.tpl.php to twig [#1843760].
Merged issue-1843762 into develop.

* issue-1843762:
  Issue [READY] Convert views/templates/views-view-summary.tpl.php to twig [#1843762].
Merged issue-1843764 into develop.

* issue-1843764:
  Issue [READY] Convert views/templates/views-view-summary-unformatted.tpl.php to twig [#1843764].
Merged issue-1843766 into develop.

* issue-1843766:
  Issue [READY] Convert views/templates/views-view-table.tpl.php to twig [#1843766].
Merged issue-1843770 into develop.

* issue-1843770:
  Issue [READY] Convert views/templates/views-view-unformatted.tpl.php to twig [#1843770].
Merged issue-1843772 into develop.

* issue-1843772:
  Issue [READY] Convert views/views_ui/templates/views-ui-display-tab-bucket.tpl.php to Twig [#1843772].
Merged issue-1843774 into develop.

* issue-1843774:
  Issue [READY] Convert views/views_ui/templates/views-ui-display-tab-setting.tpl.php to Twig [#1843774].
Merged issue-1896060 into develop.

* issue-1896060:
  Issue [READY] aggregator.module - Convert PHPTemplate templates to Twig [#1896060].
Merged issue-1898034 into develop.

* issue-1898034:
  Issue [READY] block.module - Convert PHPTemplate templates to Twig [#1898034].
Merged issue-1898050 into develop.

* issue-1898050:
  Issue [READY] book.module - Convert PHPTemplate templates to Twig [#1898050].
Merged issue-1898054 into develop.

* issue-1898054:
  Issue [READY] comment.module - Convert PHPTemplate templates to Twig [#1898054].