X ## needs check if player solved everything

[andrewschultz]

This could be just a simple flag set to false to start but true when one clue is left.

I may also wish to check this once the player solves something, if X 13 is on.

So, test cases:

1. solve all friends and super-near, then X12
2. X12, then solve all friends and super-near
   2a. if the player is warned once, don't warn them if they solve another puzzle. That's annoying.

This should be there for advanced mode, too.