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.

* Fix spelling mistake in kdsingleapplicationguard.cpp

s/emty/empty/g.

* Add fdo keywords

Add freedesktop.org keywords to desktop entry.

This allows users to search for the app in various desktop environments.

For more details, see:
    https://specifications.freedesktop.org/desktop-entry-spec/latest/ar01s05.html,
    https://bugs.debian.org/693918, and
    https://wiki.gnome.org/Initiatives/GnomeGoals/DesktopFileKeywords for

s/emty/empty/g.

Use device's immutable copy instead of rescanning.

Port away from most cases of Q_FOREACH to C++11 ranged for loop.

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

displaymanager: write processed DM list to globalstorage