Lout and Tiny extension of @Box in @Diagram

[Jeff Kingston]

Request for

    NNW:: { xsize / 4 ysize }
    NNE:: { xsize * 0.75 ysize }
    SSW:: { xsize / 4 0 }
    SSE:: { xsize * 0.75 0 }

labels in boxes.  Done.  Flowed on automatically to @ShadowBox and the
labelprox options, but I did not do it for the other shapes (@CurveBox is
harder than it looks, since the new labels could be on the curved parts).

Jeff Kingston