Skip the region page

People seem to be confused about this page, assuming that it's meant
to set the formatting of dates, currency and measurements while it's
actually about selecting the regional variant of the language selected
in the language page.

This will need design work to fix properly so, for now, we'll just
disable this page and present all the language variants in the first
page.

https://bugzilla.gnome.org/show_bug.cgi?id=732736
language: Show all locales

Instead of having the locale selection split in two pages, this shows
all locales in the first page. The country is displayed along with the
language on each row.

https://bugzilla.gnome.org/show_bug.cgi?id=732736