Issue #1881582 by sun: Change configuration overrides to use $config instead of $conf.
Issue #2182439 by tim.plunkett: Provide a \Drupal::hasService() method.
Issue #2184591 by sun: system_rebuild_module_data() adds stale/obsolete 'files' property.
Issue #2184649 by tim.plunkett: Remove LinkGenerator::getActive() and LinkGenerator::setRequest().
Issue #1981418 by andypost, pcambra, tim.plunkett, dsdeiz, alweb: Drop taxonomy_vocabulary_sort().
Issue #2177657 by martin107, InternetDevels: Replace theme() with drupal_render() in tablesort.inc.
Issue #2177663 by chakrapani, InternetDevels: Replace theme() with drupal_render() in theme.inc.
Issue #2176105 followup by sun: Installer catches exceptions and manually re-prints them; does not use error/exception handler.
Issue #1891126 by TR, YesCT, mitron: Extend / Modules page disabled red signal concerned usability participants.
Issue #2007124 by pplantinga, anirudha_3083, martin107, InternetDevels: Replace theme() with drupal_render() in authorize.php.
Issue #2187653 by ianthomas_uk: Remove comment_alphadecimal_to_int and comment_int_to_alphadecimal.
Issue #2159915 by ianthomas_uk, martin107, InternetDevels: Remove drupal_load().
Issue #2190421 by amateescu: Fix some services that shouldn't be serialized.
Issue #2177655 by chakrapani, InternetDevels, martin107 | jessebeach: Replace theme() with drupal_render() in install.core.inc.
Issue #2190427 by joelpittet, jessebeach: Replace theme() with drupal_render() in form.inc.
Issue #1939062 by steveoliver, mdrummond, jenlampton, hussainweb, Cottser, joelpittet, jerdavis, ekl1773, dale42, drupalninja99, gabesullice, c4rl: Convert theme_item_list() to Twig.
Issue #2152207 by steveoliver, joelpittet, gnuget, idflood, hussainweb, shanethehat, jenlampton, kpa, AnythonyR, EVIIILJ, kgoel, Cottser, dsdeiz, hanpersand: Convert theme_details() to Twig
Issue #1939064 by joelpittet, pwieck, farrington, mark.labrecque, Cottser, InternetDevels, mdrummond, drupalninja99, BarisW, jenlampton: Convert theme_links() to Twig.
Issue #2092343 by joelpittet, c4rl, Mark Carver: Consolidate forum.module and remove call to _theme_table_cell() within template_preprocess_forum_topic_list().
Issue #1926344 by jhodgdon, maggo, mdrummond, Cottser, dimboz | jenlampton: Consolidate search-result.html.twig and search-results.html.twig.