Issue #1898054: Convert comment module to Twig.
Issue #1898062: Convert field module to Twig.
Issue #1898038: Convert custom_block module to Twig.
Issue #1898034: Convert block module to Twig.
Issue #1939008: Convert theme_table() to Twig.
Issue #1939062: Convert theme_item_list() to Twig.
Issue #1939064: Convert theme_links() to Twig.
Issue #1939066: Convert theme_breadcrumb() to Twig.
Issue #1939068: Convert theme_image() to Twig.
Issue #1961876: Convert theme_link() to Twig.
Issue #1961872: Convert html.tpl.php to Twig.
Issue #1961870: Convert page.tpl.php to Twig.
Issue #1961868: Convert region.tpl.php to Twig.
Issue #1898460: Convert taxonomy module to Twig.
Issue #1898468: Convert user module to Twig.
Issue #1896060: Convert aggregator module to Twig.
Issue #1898050: Convert book module to Twig.
Issue #1963474: Convert ckeditor module to Twig.
Issue #1898052: Convert color module to Twig.
Issue #1898456: Convert common_test module to Twig.