Magic Cube

Squares: add meshes.
Bump version to 1.8.2

Square-2: minor.

Squares: icons.

Square-2 fix.

Square-2: progress.

Introduce Square-2 (unfinished)

Square-1: looks to be finished.

Square-1: progress with automatic scrambling.

Square-1: implement the fact that corners might bandage the puzzle.

Square-1: this is a shape-shifter; we cannot just clamp the Cubit positions to the initial list of positions.
Do so only if the minError is appropriately low.