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

Issue #1392754 by tss, justAChris, jhodgdon: Comply with new documentation standards for @file for namespaced class files

Issue #2392293 by bircher, tim.plunkett, alexpott, cilefen, gobinathm: Refactor hook_system_info_alter implementations to use ModuleUninstallValidatorInterface

Issue #2451665 by dawehner: Don't rebuild the route on ModuleInstaller::install() (30% installer speedup)

Issue #356399 by dawehner, beejeebus, catch, sidharrell, klausi, nlisgo, Josh Waihi, Berdir, martin107: Optimize the route rebuilding process to rebuild on write

Issue #2347999 by Mile23, daffie, cs_shadow, cosmicdreams: DrupalUnitTestBase is deprecated, replace with KernelTestBase

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

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

Issue #1067408 by alexpott, Jalandhar, jessebeach, Désiré, neetu morwani, dawehner, sun: Themes do not have an installation status.

Issue #2045931 by Sam152, joelpittet, LinL, Sutharsan, adsw12: Replace all module_exists() deprecated function calls.

Issue #2181811 by alexpott: System info can become inconsistent if hook_system_info_alter() makes a module required.

Issue #1199946 by alexpott, fubhy, bojanz, steinmb, chx, catch: Fixed Disabled modules are broken beyond repair so the 'disable' functionality needs to be removed.

Issue #1608842 by chx, alexpott, sun, effulgentsia, beejeebus, tim.plunkett et al: Replace list of bootstrap modules, enabled modules, enabled themes, and default theme with config.