According to the Qt-docs you *may* send the new values in the
NOTIFY signal of Q_PROPERTYs. However, since changes will lead
to a reevaluation of a whole expression, this argument will be
unused. All it does is make the code more verbose and brittle:
What happens if you send the wrong value?
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>