Provided in the default Dom0 installation as it brings a much better
usability and small packages.
KDE ships with kdialog but without a screenshot utility.
Xfce ships with xfce4-screenshooter but without a dialog utility.
Scrot and Zenity are minimal tools that works on both DEs and are very
small packages.
Fixes: https://github.com/ben-grande/qusal/issues/22
