Palisade/Loopy: button for s/maybe/yes/ (or no)

[chrisboyle]

If you play subtractively, erasing lots of edges, then you end up with lots of yellow edges which you want to turn black, and a one-shot button would be helpful. Requested by Nick Callor; I also sometimes play this way myself.

[chrisboyle]

Burak Demiralay writes:

In game loopy, yellow lines force me to tick twice for every edge. it is kind of frustrating, maybe you can put an option to remove them all for whoever wants.

...but that case might be better as a game-specific setting to start without them all. (The original case on this bug makes less sense as a setting.)