One close-button object was used for all dive pictures. This seems
like a brittle premature optimization and the pixmap is shared
anyway. Make the button a subobject of the dive picture object.
Change the object-hierarchy to be based on QGraphicsItem instead
of QObject. The QObject here is only used as a kludge to support
signals and properties (the latter are necessary for animations).
Remove a comment, which does not seem to be relevant after this
change.
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
630862971f