never move power messages with the associated pawn. fixes information leaks with moving/teleporting invisible pawns.
Don't mark tiles as unseen when not playing with fog of war.
Copy the linear/radial tile functions into GameState.

Now they can be used directly on tiles, no pawn required.
Prevent powers from spawning based on game settings.

Fog of war is the only setting at the moment, and nothing tests it.
Watchful Eye power. Acts like a non-+range pawn for extra viewing range.