Issue #2829185 by vaplas, Jo Fitzgerald, anmolgoyal74, chipway, gaurav.kapoor, mark_fullmer, amit.drupal, cilefen, longwave, xjm, wturrell, anavarre: Fix spelling errors in Drupal core comments

(cherry picked from commit 2dabd1de)

Issue #2901730 by mfernea, ankitjain28may, idebr: Fix 'Squiz.WhiteSpace.FunctionSpacing' coding standard

Issue #2867703 by Berdir: Change #action in UserLoginBlock to a #lazy_builder to avoid the route cache context

Issue #2776975 by joelpittet, dawehner, tim.plunkett, xjm, pfrenssen: March 3, 2017: Convert core to array syntax coding standards for Drupal 8.3.x RC phase

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

Issue #893868 by ericbroder, jaxxed, iMiksu, yogen.prasad, a.ross, mrfelton, VM, lauriii, Jasu_M: Login block not shown on user/register

Issue #2551453 by LoMo, Ayesh, jaxxed, LinL, madhavvyas, Miraya: Follow-up: Consistently use "email" instead of "e-mail" in Drupal

Issue #2467863 by Dom., JesseSturgis, mgifford, LewisNyman, Cliff, benjifisher, heatherwoz, crasx: Login form's aria-describeby points to an element that doesn't exist

Issue #2375695 by Berdir, EclipseGc, tim.plunkett, Wim Leers, Fabianx, dawehner: Condition plugins should provide cache contexts AND cacheability metadata needs to be exposed

Issue #2375689 by Arla, Wim Leers, dawehner, tim.plunkett, Berdir: BlockBase::blockAccess() should return AccessResult instead of a bool

Issue #2448605 by martin107, willzyx, tim.plunkett, klausi, dpopdan: Replace usages of drupal_get_destination() with the redirect destination service

Issue #2281619 by dawehner, tim.plunkett: Convert most direct usages within module code of routing related request attributes to use RouteMatchInterface instead

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

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

Issue #2277103 by tim.plunkett, pwolanin, Wim Leers, dawehner, hotpizzas: Switch Drupal::l() and LinkGenerator to expect a Url object.

Issue #2343651 by xjm, tim.plunkett, Wim Leers, dinarcon, dawehner: Remove most remaining l() calls.

Issue #2283969 by tim.plunkett: Add a protected BlockBase::blockAccess() to contain plugin-specific logic.

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

Issue #788900 by ParisLiakos, dawehner, effulgentsia, xjm, et al: Deprecate and remove usages of arg().

Issue #2121175 by Codenator, tim.plunkett, cosmicdreams, jayeshanandani, grom358, ianthomas_uk, Xano: Remove usage of drupal_get_form().

Issue #2085201 by jessebeach, tim.plunkett, dawehner, yoroy: Use sensible block categories (rather than module-name categories).

Issue #1951386 by benjy, theduke, andypost, tim.plunkett: Fixed Extend BlockPluginInterface::access to allow passing in an account.

Issue #1927608 by EclipseGc, tim.plunkett, effulgentsia: Remove the tight coupling between Block Plugins and Block Entities.

Issue #1987298 by tim.plunkett, quicksketch: Shorten directory structure and PSR-0 namespacing for plugins.

Issue #1969276 by effulgentsia, tim.plunkett, EclipseGc: Refactor block plugins to make room for a BlockBase::build() implementation.

Issue #1849752 by effulgentsia, Berdir, jibran, neclimdul: Abstract non-Drupal-specific parts of AnnotatedClassDiscovery into a Drupal\Component base class.