Issue #1772708 by alexpott, sun, chx, catch, beejeebus: Fixed The configuration directories can not be outside of DRUPAL_ROOT.

Issue #1754208 by PrabhuG, webflo, savithac, Gábor Hojtsy: Convert hook_mail() and hook_mail_alter() to langcode.

Issue #1627006 follow-up by YesCT, webflo, Gábor Hojtsy: CMI conversion and minor followups to 'Collect project information for translation update'.

Issue #1757566 by alexpott, aspilicious: Convert user account e-mail templates to configuration system.

Issue #1542620 by djdevin, rootatwc: Fixed Fatal errors when file permissions for settings.php are messed up (can't read file).

Issue #1739592 by Albert Volkman, andy.hails, dawehner: Fix up docs of a few language-related functions

Issue #362889 by Xano, andypost, dawehner, Davy Van Den Bremt, cweagans, sun: Move drupal_common_theme() from common.inc into theme.inc.

Issue #1164760 by tim.plunkett, LoMo, Mile23, David_Rothstein, webchick, Bojhan, yoroy, naught101: [meta] Rename 'Modules' in toolbar to 'Extend'.

Revert "Issue #1772708 by alexpott: Fixed The configuration directories can not be outside of DRUPAL_ROOT."

This reverts commit e003e4c5.

Issue #813750 by joachim, zuuperman, swentel: Fixed don't show 'Custom display settings' on Manage Display if there's only one view mode.

Issue #1658842 by penyaskito, attiks, webflo: Added Introduce a translations:// stream wrapper to access the .po file directory.

This reverts commit 81666e2b. Sorry, did NOT mean to push that; was testing the CMI UI patch.

Issue #1775780 by tim.plunkett, alexpott: Fixed Needs tests: Forum module's block configuration for block.active.limit and block.new.limit .

Issue #218755 by jstoller, Gábor Hojtsy, stevector, mradcliffe, agentrickard, catch, Crell: Added Support revisions in different states.

Issue #1646580 by Gábor Hojtsy: Add changelog for config having language variants and runtime values

Issue #1498874 by peximo, plach, Gábor Hojtsy, attiks: Provide language awareness to entity forms (introduce the form language concept).

Issue #1057912 by bfroehle, mgifford, bowersox, tarekdj, geerlingguy, irunflower, hgurol: Fixed Weird Border on Vertical Tabs with Google Chrome and Safari caused by .element-invisible.

Issue #1055862 by sun, catch, pillarsdotnet, danillonunes: Require sites.php to opt-in for multi-site support/functionality.

Issue #1067120 by BTMash, DamienMcKenna, corvus_ch, valthebald, mrfelton, fgm, Dave Reid: Added Missing hook_taxonomy_term_view() or hook_entity_view() when viewing a term.

Issue #365615 by attiks, smokris, penyaskito, Gábor Hojtsy, Bojhan, WormFood, yang_yi_cn: Fixed Language detection not working correctly for most Chinese readers.