Issue #2457887 by prateekMehta, stefan.r, rpayanm, alexpott: Use Utility\SafeMarkup class instead of Utility\String for placeholder(), checkPlain(),format() functions

Issue #2090115 by alexpott, xjm: Don't install a module when its default configuration has unmet dependencies

Issue #2416409 by alexpott, bojanz: Delete dependent config entities that don't implement onDependencyRemoval() when a config entity is deleted

Issue #2420107 by alexpott: Determine which config entities can be fixed and which will be deleted when a dependency is removed

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

Issue #1728804 by Berdir: Introduce (Content)EntityDeleteForm and children to handle entity deletions

Revert "Issue #2388749 by alexpott, adci_contributor, ParisLiakos: Register symfony's mime guessers if they are supported"

This reverts commit 4dae1d99.

Issue #2388749 by alexpott, adci_contributor, ParisLiakos: Register symfony's mime guessers if they are supported

Issue #2142653 by corbacho, sqndr, LewisNyman, floretan, BarisW, G-raph, JamesLefrère, lokapujya, LoMo, Outi: Change default logo filetype to .svg and add an SVG version of Druplicon

Issue #2140511 by alexpott, Gábor Hojtsy, swentel, babruix, ohthehugemanatee, jessebeach, Berdir: Configuration file name collisions silently ignored for default configuration

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

Issue #2040135 by Wim Leers, Berdir: Caches dependent on simple config are only invalidated on form submissions

Issue #2151469 by rpayanm, lokapujya, JeroenT, alansaviolobo, Richard Damon, pflame, ianthomas_uk: Clean-up usage of deprecated list_themes() and _system_rebuild_theme_data() in favor of theme_handler service.

Issue #2309737 by rpayanm, hussainweb, max-kuzomko, herom, millerbennett, ianthomas_uk, quietone, Sutharsan, sumitmadan, toddmbloom: Remove deprecated format_plural usage

Issue #1719648 by joachim, ttkaminski, kshama_deshmukh: ModuleInstaller::install() silently fails if a module isn't in the file system

Issue #2353357 by Berdir: hook_stream_wrappers_alter() is broken since modules are not loaded on demand, also change to an event since it's the last hook that forces this during bootstrap

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

Issue #2278017 by cilefen, bircher, effulgentsia: When a content entity type providing module is uninstalled, the entities are not fully deleted, leaving broken reference

Issue #1759090 by andrewmacpherson, InternetDevels, jjcarrion: Remove redundant CSS from theme settings form

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

Issue #2294571 by znerol, effulgentsia: Redirect anonymous users to login page from an exception listener instead of in MaintenanceModeSubscriber and restrict access to the my-account link to authenticated users.

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

Issue #2347465 by tim.plunkett, dawehner, cilefen: Convert all instances of #type link/links to convert to use routes.

Issue #2345753 by tim.plunkett, dawehner, Wim Leers, damiankloip: Remove url(current_path()) and url(NULL) with <current> and <none>.

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

Issue #1869476 by rteijeiro, LewisNyman, lauriii, Wim Leers, mdrummond, swentel, hosef, cbiggins, larowlan, sun, EclipseGc, Gábor Hojtsy: Convert global menus (primary links, secondary links) into blocks.

Issue #2340251 by iMiksu, alexpott, tim.plunkett, dawehner, Wim Leers: Remove most remaining url() calls.

Issue #2340123 by Wim Leers: Setting cache tags can be tricky: use strings instead of nested arrays to improve DX.

Issue #2342435 by tstoeckler, webchick: Don't show 80 bazillion test modules on the modules page when in development mode.

Issue #2337709 by tim.plunkett: Convert form_state_values_clean() to FormStateInterface::cleanValues().