Issue #977844 by Wim Leers: Remove the 'every_page' option for CSS/JS assets: it is confusing, even damaging

Issue #2395853 by LewisNyman, Manjit.Singh, nlisgo, pjbaert, Branislav Bujisic, pguillard, gavin.hughes, onelittlebecca, alisonjo2786, camoa, DickJohnson, manmohandream, davidhernandez, kgoel: Split system.module.css and system.theme.css files into SMACSS style components

Issue #2056089 by BarisW, TR, mgifford, rodvolpe, Dom., nambisolo, nod_, katewelling, Manjit.Singh, jhodgdon, Bojhan, Wim Leers: UI problems on the Modules/Extend page

Issue #2472431 by davidhernandez, yannickoo, cilefen, LewisNyman: Do not load normalize.css in all themes, load it in Classy

Issue #2429443 by vijaycs85, rteijeiro, penyaskito, gloob, xjm, nod_, geertvd, pjonckiere, alexpott, Wim Leers, Gábor Hojtsy, Fabianx, tim.plunkett: Date format form is unusable

Revert "Issue #2429443 by vijaycs85, rteijeiro, penyaskito, gloob, xjm, nod_, geertvd, Wim Leers, Gábor Hojtsy, Fabianx, pjonckiere, tim.plunkett: Date format form is unusable"

This reverts commit 37e278b4.

Issue #2429443 by vijaycs85, rteijeiro, penyaskito, gloob, xjm, nod_, geertvd, Wim Leers, Gábor Hojtsy, Fabianx, pjonckiere, tim.plunkett: Date format form is unusable

Broke testing UI. Reverted.

This reverts commit dc5ef576.

Issue #2378095 by Wim Leers, Devin Carlson: Convert all remaining attached individual CSS/JS assets to attached asset libraries

Issue #1996238 by sun, nod_, damiankloip, Wim Leers, longwave, alexpott, Xano, mdrummond, Mark Carver, Jeff Burnz, highrockmedia, joelpittet, et al: Replace hook_library_info() by *.libraries.yml file.