Hints to the user

[heatherleaf]

If we have a way to find the shortest solution (issue #58), then this can be used to give hints to a user.

E.g., when the user has gone in the wrong direction for some time (or not selected anything), the system can hint by highlighting the location to click, or even by highlighting the correct menu item.

[heatherleaf]

Update to the formulation: If the user gets stuck, the system should help

• there could be a "help" button
• or the system could make the problem easier, 
if the user doesn't make any progress

What kind of help is there?

• hint: the system highlights the correct menu, 
and/or the correct menu choice
• simplify: reduce the size of the menus 
(i.e., filter the menu choices)

[heatherleaf]

Depends on #98