Issue #1999448 by chertzog, aaronott, chrisjlee, daffodil_naveen, kim.pepper: Use Symfony Request for user module.

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

Issue #1818570 by Berdir, effulgentsia, das-peter, andypost: Convert users to the new Entity Field API.

Issue #1620010 by dawehner, ParisLiakos, plach, jibran: Move LANGUAGE constants to the Language class.

Issue #1913618 by tim.plunkett, amateescu: Convert EntityFormControllerInterface to extend FormInterface.

Issue #1479454 by Hugo Wetterberg, galooph, andypost, marcingy, heyrocker, larowlan, alexpott, tim.plunkett, fubhy, sun, dawehner: Convert user roles to configurables.

Revert "Issue #1479454 by Hugo Wetterberg, galooph, dawehner, andypost, marcingy, heyrocker, larowlan, alexpott, tim.plunkett, fubhy, sun: Change notice: Convert user roles to configurables."

Broke testbot. :(

This reverts commit 2ae15972.

Issue #1479454 by Hugo Wetterberg, galooph, dawehner, andypost, marcingy, heyrocker, larowlan, alexpott, tim.plunkett, fubhy, sun: Change notice: Convert user roles to configurables.

Issue #787876 by David_Rothstein, zero2one: Inline code comment followup for 'My Account' fills the first password field.

Issue #1168246 by sun, mgifford, Manuel Garcia, mbrett5062, ry5n, Everett Zufelt, nod_, aspilicious, deviantintegral, tim.plunkett: Freedom For Fieldsets! Long Live The DETAILS.

Issue #1292470 by sun, tim.plunkett, Berdir, moshe weitzman, pcambra, Niklas Fiekas, andypost et al: Convert user pictures to Image Field.

Issue #1754208 by PrabhuG, webflo, savithac, Gábor Hojtsy: Convert hook_mail() and hook_mail_alter() to langcode.

- Patch #322995 by Schnitzel, c31ck, webflo, penyaskito: provide a distinct administration user interface language option.

Issue #1496534 by cosmicdreams, alexpott, aspilicious, kim.pepper, acrollet, dagmar, beejeebus, wizonesolutions | heyrocker: Convert account settings to configuration system.

Issue #1280996 by tarmstrong, vasi1186, fastangel, dawehner, tobiasb: New language_select() element type for form API.