Change ops.SelectByPoint to rely on object shapes rather than bounding
    boxes.  Requires:
    
    PointOnObject
    PointOnLine PointInBox
    PointOnCircle PointInCircle
    PointOnEllipse PointInEllipse
    PointInPolygon (?) PointInSpline (?)


Add line style/thickness operations.

Clip to bounding box when drawing text.
