Fixed #19182 -- Fixed ModelAdmin.lookup_allowed to work with ('fieldname', SimpleListFilter) syntax.

Thanks gauss for the report.
Fixed #21216 -- Allow `OneToOneField` reverse accessor to be hidden.
Fixed #19277 -- Added LocaleMiddleware.response_redirect_class

Thanks ppetrid at yawd.eu for the suggestion.
Fixed #21218 -- Typo on docs/howto/upgrade-version.txt

Thanks ryan at ryangallen.com for the report.