enhancement: Make it easier to define a straight segment

[GoogleCodeExporter]

When driving libarea with Python, it's a bit of a pain to add a straight 
segment to a curve.  You end up with something like:
   c.append(Vertex(0, p1, pz))
where 'pz' is never used, and '0' specifies a straight segment.

With the attached patch, this can be written instead as
   c.append(Vertex(p1))

Original issue reported on code.google.com by [email protected] on 26 Sep 2010 at 6:40

Attachments:

• 0002-Make-it-easier-to-define-a-straight-segment.patch