Issue #2144669 by Mile23, daffie, Nitesh Sethia: Improve/Refactor TestBase Through Expanded Unit Testing

Issue #2363341 by tim.plunkett, donquixote, adci_contributor: Throw exception in Drupal::service() and friends, if container not initialized yet

Revert "Issue #2144669 by Mile23, Nitesh Sethia: Improve/Refactor TestBase Through Expanded Unit Testing"

This reverts commit 921317dc.

Issue #2417515 by idebr: TestBase::prepareDatabasePrefix() refers to DrupalWebTestCase that has been renamed

Issue #2050759 by tim.plunkett, fietserwin: Move drupal_chmod and other code in file.inc to a Drupal\Core\File\FileSystem class

Issue #2381763 by chx, webflo: Adjust the order of container yamls to override settings per environment

Issue #2406543 by alexpott: Remove ConfigFactory::setOverrideState and ConfigFactory::getOverrideState()

Issue #2392319 by alexpott, effulgentsia: Config objects (but not config entities) should by default be immutable

Issue #2382195 by tibbsa, subhojit777, tadityar, cilefen, Mile23: Clean-up simpletest module test members - ensure property definition and use of camelCase naming convention

Issue #2395395 by alexpott, effulgentsia, Gábor Hojtsy: TestBase lacks a config method to be used consistently in tests

Issue #2170235 by Berdir, penyaskito, larowlan, alexpott, sushyl: file_private_path should be in $settings, like file_public_path

Issue #2183983 by Gábor Hojtsy, vijaycs85, Berdir, Wim Leers, webflo, alexpott: Find hidden configuration schema issues

Issue #2324055 by dawehner, cilefen, znerol: Split up the module manager into runtime information and extension information

Issue #2028109 by tim.plunkett, almaudoh, twistor, larowlan, slashrsm, Berdir, Arla, neclimdul, Cottser: Convert hook_stream_wrappers() to tagged services.

Issue #2343661 by larowlan, tim.plunkett | xjm: Rename l() to _l() and url() to _url(), and document replacements.

Issue #1860594 by penyaskito, damiankloip, xjm, alexpott, sun: Ensure that randomString() always returns a character that needs to be escaped for HTML.

Issue #2284103 by alexpott, fabpot, damiankloip, Xano, Xen, Berdir: Fixed Remove the request from the container.

Issue #697760 by sun: Replace getInfo() in tests with native phpDoc + annotations (following PHPUnit).

Issue #2239969 by znerol, alexpott, neclimdul, sun: Fixed session of (UI) test runner leaks into web tests.

Issue #2016629 by larowlan, neclimdul, sun, alexpott, jibran, ParisLiakos, donquixote, effulgentsia, msonnabaum: Refactor bootstrap to better utilize the kernel.

Issue #950534 by mparker17, mgifford, Mixologic, jbloomfield, erinclerico, theMusician, wmostrey | zirvap: [policy] Consistently use email instead of e-mail in Drupal.

This reverts commit 2cd0b096.

Revert "Issue #2016629 by larowlan, neclimdul, sun, alexpott, jibran, ParisLiakos, donquixote, effulgentsia, msonnabaum: Refactor bootstrap to better utilize the kernel."

This reverts commit cda051c4.

Issue #2016629 by larowlan, neclimdul, sun, alexpott, jibran, ParisLiakos, donquixote, effulgentsia, msonnabaum: Refactor bootstrap to better utilize the kernel.

This reverts commit 78d18c8d.

Broke HEAD. Temporary rollback.

This reverts commit 5a3ef306.

This reverts commit 341b903d.