For most dialogs it would be much safer to make them Qt::WindowModal to
the parent (MainWindow).
For now we are not doing this for the preferences dialog as there are
situations where the user might want to be able to move it around and even
interact with the main window.
Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>