- Use a named enum instead of a collection of booleans
- Support old-style configuration but complain about it
- Update AppImage config as well
The new setup allows four different restart modes: never,
always, user-unchecked and user-checked. The user-modes
are interactive and give the user a choice (defaulting to
unchecked-don't-restart and checked-do-restart respectively).
The non-interactive versions vary in how they are
displayed.
- These methods are used for multi-page view-steps, which are rare.
For all the others, just drop the empty implementation and defer
to the base class.