Issue #2047619 by dawehner, pwolanin, tstoeckler, thedavidmeister: Add a link generator service for route-based links.

Issue #2057155 by pwolanin, dawehner: Add a generateFromRoute() method on the url generator to accept options like url().

Stupid commit message. :P Fixing. :P

This reverts commit 838bf21e.

Issue #2068217 by thedavidmeister: Fixed array('hook') syntax for suggestions is broken for #theme_wrappers().

Issue #2032535 by dawehner, katbailey, pwolanin, Crell: Resolve 'title/title callback' by adding a _title propery on the route and allow a title be part of the render array.

Issue #1957142 follow-up by dawehner, jibran: Fix a few more config() => Drupal::config() stragglers.

Issue #1476810 by Spleshka, franz: Fixed drupal_serve_page_from_cache() can serve uncompressed data with Content-Encoding gzip header with page_cache_without_database = 1.

Issue #1164682 by mgifford, thedavidmeister, good_man, mvc, clemens.tolboom, sxnc, lazysoundsystem: Fixed links with a known language need language identifier.

Issue #1941288 by larowlan, effulgentsia, dawehner, nod_: Fixed Regression: ajaxPageState not being updated with AjaxResponse, assets (js/css) being added twice.

Issue #1855260 by beejeebus, msonnabaum, larowlan: Fixed Page caching broken by accept header-based routing.

Issue #2028499 by tsphethean, damiankloip, dawehner: Drupal_sort_weight() should be converted to a class.

Issue #2042285 by thedavidmeister, jenlampton, Mark Carver: #theme_wrappers() should be able to have a unique set of variables per wrapper hook.

Issue #2045923 by drupalrv, tim.plunkett: Replace all module_invoke_all() deprecated function calls in procedural code.

Issue #2052389 by pwolanin: Fixed All elements added to the Request attributes should have a _ prepended unless they come from the path.

Issue #2015307 by thedavidmeister, meeli, Cottser: Overhaul docs for drupal_render so they actually say what the function does and what properties it uses

This reverts commit 127b54a6.

Issue #2036799 by steveoliver: Drupal_pre_render_link() contains phptemplate example code; needs twig code.

Issue #352951 by Wim Leers, mfer, mcjim, larowlan, RobLoach, sdboyer, Owen Barton, JohnAlbin: Make JS & CSS Preprocessing Pluggable.

Issue #2012812 by thedavidmeister, pwieck: drupal_render() can't distinguish between empty strings from theme() from an implemented hook and no hook being matched.

Issue #2010024 by damiankloip, dawehner, ParisLiakos: Move url related functions to a new Url component.

Issue #1754246 by webflo, swentel, penyaskito, andypost, alexpott, YesCT, dagmar: Languages should be configuration entities.

Issue #1869600 by linclark, scor, jesse.d: Refactor RDF mappings to be inline with the new Entity Field API.

Revert "Issue #2012812 by thedavidmeister, pwieck: drupal_render() can't distinguish between empty strings from theme() from an implemented hook and no hook being matched."

This reverts commit 431dc2e3.