Issue #2457781 by prateekMehta, stefan.r, AjitS, hussainweb: Use Utility\Html class instead of Utility\String for decodeEntities() function

Issue #2404603 by mpdonadio, dawehner, larowlan, RavindraSingh: Add proper support for Url objects in FieldPluginBase::renderAsLink(), so we can remove EntityInterface::getSystemPath()

Broke testing UI. Reverted.

This reverts commit dc5ef576.

Issue #2382543 by rpayanm, ianthomas_uk: Remove usage of drupal_html_class() and drupal_clean_css_identifier()

Issue #2384165 by tibbsa: Clean-up Contextual module test members — ensure property definition and use of camelCase naming convention

Issue #2371457 by DuaelFr: Replace inappropriate translatatable string in core/modules/contextual/contextual.module.

Issue #2350949 by Wim Leers: Add hook_page_attachments(_alter)() and deprecate hook_page_build/alter().

Needs more discussion.

This reverts commit b983fad1.

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

Issue #2350301 by mitrpaka: Replace extend of deprecated DrupalUnitTestBase with KernelTestBase in Contextual.

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

Issue #2221433 by damiankloip, dawehner: Clean up views rendering. Move stuff from template_preprocess_views_view(), into a #pre_render callback.

Issue #2091311 by mparker17, minneapolisdan, benjf, er.pushpinderrana, wzoom, jhodgdon, batigolix | ifrik: Update hook_help for Contextual Link module.

Issue #2309137 by longwave, sqndr | LewisNyman: Remove quotes from all background-image: url() properties.

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

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

Issue #2243549 by agerson, cs_shadow | jhodgdon: Text changes needed as follow-up to Menu UI module rename.