locale -a returns the locales using ".utf8" names rather than ".UTF-8".
The case-insensitive match does not help because it is "utf8" rather
than "UTF-8". So we need to match both with and without the dash.

The arrow no longer changes direction depending on whether
the button is clicked or not.

The button is "not checked" by default, and becomes
checked when clicked; the packageview becomes visible
when the button is checked.

CAL-385 #close

CAL-390 #close

Pass the full name directly to useradd instead, using the "-c" (comment)
parameter, which is "currently used as the field for the user's full
name" according to the documentation.

The chfn utility is no longer installed by default on current Fedora
releases due to its dependency on libuser. (They split out chfn and chsh
from util-linux into an optional subpackage.) It could be added as a
dependency of Calamares, but since it is needed inside the chroot, it
has to be on the base live image, not the overlay. Thus, to allow
testing Calamares with a simple "dnf install calamares" again, the
dependency needs to go away. And it is unnecessary anyway.

In order to avoid deep copies, Qt containers over which we iterate must be const
The remaining unported cases require qAsConst (Qt 5.7) or std::as_const (C++17)

This fixes CAL-385 #close

This is disabled by default. To enable, provide a geoipUrl setting in
locale.conf.
Relies on the RequirementsChecker output, in the welcome module.

Since our default locale setting is **en_US** anyway, it makes more sense to default to New York.

Also fix error reporting.
Move guesswork to LocaleConfiguration + a total rewrite.
Locale is now a LocaleConfiguration, that converts to QMap.