Split into classes for Fill, Stroke, and SatinColumn. Renamed params to be
the same across XML attributes and OptionParser. Added distinct stitch length
params for satin underlay. Renamed "satin underlay" to "contour underlay" and
split out "center walk underlay" and "zigzag underlay".
The code is ten times more readable, parameters make more sense, and everything
is specified by the user in millimeters. Basically, everything is way better.