Issue #2228799 by pmagunia, mohit_aghera, rpayanm, lalitware, AkashKumar07, quietone, bnjmnm: Change page title "Content language" when Content Translation module is enabled

Issue #2422685 by balagan: Language negotiation configuration page titles inconsistent, should not even mention "negotiation"

Issue #2271005 by martin107, YesCT, alimac, mrjmd: Rename Language module's LanguageInterface to ConfigurableLanguageInterface and Language to ConfigurableLanguage.

Issue #1987726 by vijaycs85, disasm, YesCT, pdrake, tstoeckler, dawehner, Xano, likin, stella, andypost, prateek479, Gábor Hojtsy, kgoel: Convert language content page related callback to new style controller.

Issue #2086485 by brianV, jibran, pwolanin, disasm: Convert language_negotiation_configure_form() to the new form interface.

Issue #2102125 by dawehner, tim.plunkett, neclimdul, pwolanin, YesCT, damiankloip, Tim Bozeman: Big Local Task Conversion.

Issue #2004878 by kalabro, DmitryDrozdik, YesCT: Config page title 'Content language settings' misleading after translation is enabled.

Issue #2095121 by clemens.tolboom, jibran: Ensure every path in routing.yml files has a leading slash.

Issue #2089635 by tim.plunkett, disasm, larowlan: Convert non-test non-form page callbacks to routes and controllers.

Issue #2051097 by dawehner, Manuel Garcia, tlattimore, neclimdul: Change 'pattern' to 'path' in *.routing.yml files.

Issue #1981368 by tim.plunkett, Crell, webchick: Convert all routes to 'module_name().foo_bar()' naming convention.

Issue #2003592 by andypost, mhagedon, webflo: Convert language_admin_add_form() and language_admin_edit_form() to a Controllers.

Issue #1946426 by ramlev, pfrenssen, foopang, webflo, David Hernández, vijaycs85, disasm, tim.plunkett: Convert all of confirm_form() in language.admin.inc to the new form interface.

Issue #2005778 by webflo, naxoc, penyaskito, andypost, vijaycs85, plopesc, maggo: Convert language_admin_overview_form() to a Controller.