AbstractCoord.__str__ doesn't mod the values down

[kronmillerg]

def __str__(self):
    cx, cy = self.chunk
    bx, by = self.build
    ux, uy = self.unit
    return "({cx}.{bx}.{ux}, {cy}.{by}.{uy})".format(
        cx=cx, cy=cy, bx=bx, by=by, ux=ux, uy=uy
    )

So for Coord.fromCBU((0, 1), (0, 5), (0, 3)) we get "(0.0.0, 1.15.33)" (if I've remembered the scale factors correctly) where we should get "(0.0.0, 1.5.3)".