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

Revert "Issue #2273923 by mpdonadio, pfrenssen, dawehner, xjm, cilefen: Remove html => TRUE option from l() and link generator"

This reverts commit 0bcabf50.

Issue #2273923 by mpdonadio, pfrenssen, dawehner, xjm, cilefen: Remove html => TRUE option from l() and link generator

Issue #2384527 by tadityar, areke, rpayanm, preshetin: Make the class variables protected for ShortcutSet

Issue #2362227 by dawehner, mpdonadio, znerol, tim.plunkett, skipyT: Replace all instances of current_path()

Issue #2235901 by alexpott, mdrummond, iMiksu, sun, Wim Leers: Remove custom theme settings from *.info.yml

Issue #2354177 by yched: Shortcut::getRouteParams() should be named getRouteParameters() for consistency.

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

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 #2328411 by dawehner, geerlingguy, herom: Convert all permissions to yml files and permission callbacks.

Issue #791072 by Danny.Wouters, swentel, lz1irq, David_Rothstein, jbrown: Fixed Inline deletion of shortcut should not be confirmed.

Issue #2320037 by Gábor Hojtsy: Fixed Non-fieldable entities (with only base fields) cannot be configured translatable, eg. shortcuts.

Issue #2322063 by Temoor: Replace all instances of shortcut_set_load(), entity_load('shortcut_set') and entity_load_multiple('shortcut_set') with static method calls.

Issue #2238217 by effulgentsia, neclimdul, martin107, tim.plunkett, cweagans, kim.pepper, xjm: Introduce a RouteMatch class.

Issue #2190313 by pfrenssen, Berdir, amateescu, ianthomas_uk: Add $EntityType::load() and loadMultiple() to simplify loading entities.

Issue #2183113 by jhodgdon, effulgentsia, tim.plunkett, herom, larowlan: Update hook_help signature to use route_name instead of path.

Issue #2221695 by brantwynn, ianthomas_uk, grom358, ParisLiakos, Jalandhar: Remove uses of deprecated URL functions.

Issue #2226903 by pwolanin, dawehner, tvn, martin107, jessebeach: Step 1: Move static menu links to yml files.

Issue #2178725 by pwolanin, crowdcg, effulgentsia, Sutharsan: Make all core menu link machine names and the corresponding route names match.

Issue #1316692 by tim.plunkett, dawehner: Convert hook_admin_paths() into declarative properties on routes.