Issue #2185843 by Cottser: Add joelpittet to the list of theme system maintainers in MAINTAINERS.txt.

Issue #2180627 by jessebeach, Wim Leers: Remove caption filter's caption-specific alignment classes.

Issue #1926344 by jhodgdon, maggo, mdrummond, Cottser, dimboz | jenlampton: Consolidate search-result.html.twig and search-results.html.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 #1939064 by joelpittet, pwieck, farrington, mark.labrecque, Cottser, InternetDevels, mdrummond, drupalninja99, BarisW, jenlampton: Convert theme_links() 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 #1939062 by steveoliver, mdrummond, jenlampton, hussainweb, Cottser, joelpittet, jerdavis, ekl1773, dale42, drupalninja99, gabesullice, c4rl: Convert theme_item_list() to Twig.

Issue #2177655 by chakrapani, InternetDevels, martin107 | jessebeach: Replace theme() with drupal_render() in install.core.inc.

Issue #2007124 by pplantinga, anirudha_3083, martin107, InternetDevels: Replace theme() with drupal_render() in authorize.php.

Issue #1891126 by TR, YesCT, mitron: Extend / Modules page disabled red signal concerned usability participants.

Issue #2176105 followup by sun: Installer catches exceptions and manually re-prints them; does not use error/exception handler.

Issue #2171269 by effulgentsia, Wim Leers, InternetDevels, snig: Handle block rendering's #attributes correctly (fixes in-place editing of custom blocks).

Issue #2177653 by jessebeach, joelpittet, InternetDevels: Replace theme() with drupal_render() in form.inc.

Issue #2160575 by agentrickard, amateescu, plopesc: Option widgets integration is broken for the entity reference field.

Issue #2181289 by mradcliffe: Prevent exceptions on missing cache table during cache clear for pgsql.

Issue #2181855 by Cottser: Don't let ViewTestBase hog the useful assertBlockAppears and assertNoBlockAppears methods.

Issue #2185831 by tim.plunkett: Split up ParamConverterManager and stop throwing NotFoundHttpException.