Ignore project files for all versions of QtCreator.
Display custom options directly on the configure screen.
Set initial values for custom options.
Make custom sliders and textboxes wider.
A bit more sophisticated layout for custom options.
For custom sliders, show the current value in the label.
Add a function to config that tells the total number of children.
Display custom options in sections; don't display inactive options.
Make option_display::process_event non-pure virtual.