Issue #1493324 by tim.plunkett, dmsmidt, mgifford, bleen18, davidhernandez, crasx, mparker17, stefan.r, YesCT, joelpittet, tstoeckler, larowlan, vijaycs85, swentel, rpayanm, Bojhan, LewisNyman, emma.maria, BarisW, njbarrett, rteijeiro, nod_, sun, joshtaylor, mrjmd, webchick, marcvangend, kattekrab, SKAUGHT, bowersox, andrewmacpherson, Manjit.Singh, RavindraSingh, Wim Leers, BLadwin, aspilicious, mortendk, mausolos, jessebeach, Gábor Hojtsy, anandps, falcon03, franz, andypost, rooby, rootwork, Cottser, Xano: Inline form errors for accessibility and UX

Issue #2489664 by sumitmadan, davidhernandez, Manjit.Singh, Cottser: Remove unnecessary markup from core templates, a.k.a. divitis

Issue #2407725 by mortendk, sivaji@knackforge.com, rteijeiro, Manjit.Singh: Remove classes from system templates d*.html.twig

Issue #2152217 by joelpittet, mgifford, vijaycs85, jjcarrion, sun: Remove theme_form_required_marker() from the theme system - use CSS instead.

Issue #2047227 by StephaneQ, SeanKelly, richardj: Update templates to leverage support for the Twig {% trans %} tag extension.

Issue #1963476 by widukind, joelpittet, jenlampton, tlattimore, kattekrab, siccababes, adamcowboy: Datetime.module - Convert theme_ functions to Twig.