More options to ListView section header placing

Many people seem to want to do things like described in this mailthred: http://lists.trolltech.com/pipermail/qt-qml/2010-August/000891.html
E.g. have a property in ListView like: section.stickiness with possible values (None, ActiveOnTop, Stacked) where none would work as now (section headers scroll along with the list items), ActiveOnTop would always show the section header of the topmost list item and Stacked would leave all passed section headers stacked on top of the list (and on the delegate one could then e.g. scroll to the beginning of that section)