* We need to inherit to chain these two, as otherwise when the tree view
delegate calls sizeHint() it passes to the tree widget delegate, but
then has no way to return back to the tree view for the overridden
initStyleOption.
* If there was a built-in way to chain delegates like styles (which
solve this problem by calling back to baseStyle when going from one
function to another), or better yet a way to avoid the base
QStyledItemDelegate initStyleOption from completely trampling all over
the option passed in to any function, this wouldn't be necessary.