Issue #2329453 by alexpott, joelpittet, hussainweb, kaidjohnson, andriyun, JohnAlbin, mirie, steveoliver, quicksketch, geerlingguy, RobLoach, jenlampton, SebCorbin, pablo.guerino, afoster, markcarver, danbohea, andypost, catch, donquixote, marcvangend, David_Rothstein, LewisNyman, neclimdul: Ignore front end vendor folders to improve directory search performance

(cherry picked from commit 1694030b)

Issue #2605654 by Mile23, donquixote, dawehner, alexpott, catch: Modify Drupal\Core\Extension\ExtensionDiscovery to allow for scanning multiple file systems, enabling vfsStream testing

Issue #2721921 by er.pushpinderrana, Pashupathi Nath G, shashikant_chauhan, joachim: @code tag showing on docs for ExtensionDiscovery

Issue #2716685 by Mile23: Part 2: Fix several errors in the 'Drupal.Commenting.DocComment' coding standard

Issue #2665992 by alexpott, klausi, heykarthikwithu, xjm, tstoeckler: @file is not required for classes, interfaces and traits

Issue #2538108 by dawehner, jhedstrom: Add hook_post_update_X() for data value updates to reliably run after data format updates

Issue #2384675 by sidharrell, cilefen, Mile23, damiankloip, dawehner, Wim Leers, alexpott, neclimdul: Deprecate conf_path()

Issue #1081266 by stefan.r, mikeytown2, jeroen.b, tsphethean, mfb, joseph.olstad, marcelovani: Avoid re-scanning module directory when a filename or a module is missing

Issue #2395143 by amateescu, Fabianx, Berdir, beejeebus, dashaforbes, alexpott, larowlan, znerol, dawehner, catch, neclimdul, yched, fgm, effulgentsia: YAML parsing is very slow, cache it with FileCache

Revert "Issue #2395143 by amateescu, Fabianx, Berdir, beejeebus, dashaforbes, larowlan, dawehner, catch, alexpott, neclimdul, yched, znerol, fgm, effulgentsia: YAML parsing is very slow, cache it with FileCache"

This reverts commit 4192117d.

Issue #2395143 by amateescu, Fabianx, Berdir, beejeebus, dashaforbes, larowlan, dawehner, catch, alexpott, neclimdul, yched, znerol, fgm, effulgentsia: YAML parsing is very slow, cache it with FileCache

Issue #2328111 by dawehner, martin107, neclimdul: Replace most instances of the DRUPAL_ROOT constant with the app.root container parameter.

Issue #2318847 by tstoeckler: Fixed ExtensionDiscovery does not allow the value of the "type" key to be wrapped in quotes.

Issue #2209293 by sun, xjm: Remove core compatibility check in ExtensionDiscovery; obsolete with Migrate in core.

Issue #2198713 by tstoeckler: Add a settings.php variable to allow to discover/enable test extensions at regular runtime.

Issue #2216695 by sun, Damien Tournoud, Wim Leers, brantwynn: Run-tests.sh broken on OS X ('Too many open files').

Issue #340723 by ParisLiakos, sun, Berdir, glennpratt, Cottser, swentel, alexpott, tstoeckler, Xano, tim.plunkett, BassistJimmyJam | beejeebus: Make modules and installation profiles only require .info.yml files.

Revert "Issue #340723 by ParisLiakos, sun, Berdir, glennpratt, Cottser, swentel, tstoeckler, Xano, tim.plunkett, BassistJimmyJam: Make modules and installation profiles only require .info.yml files."

This reverts commit b4c561d0.

Issue #340723 by ParisLiakos, sun, Berdir, glennpratt, Cottser, swentel, tstoeckler, Xano, tim.plunkett, BassistJimmyJam: Make modules and installation profiles only require .info.yml files.

Issue #2210197 by sun, longwave, Sutharsan: Remove public access to Extension::$type, ::$name, ::$filename.

Revert "Issue #2210197 by sun, longwave: Remove public access to Extension::$type, ::$name, ::$filename." Broke 'drush en simpletest' on testbots

This reverts commit 2c51074d.

This reverts commit ae8be3cc.