In pull #383 we changed the behavior of kmlparser.py to use the <Placemark> <name/> element as the shape_id when generatings shapes from LineString features.  However, that broke a test for kmlwriter.py where the output of kmlwriter.py is fed immediately into kmlparsery.py.  The issue is that kmlwriter.py also outputs stop-pattern LineStrings for each route, where the name associated with each feature is not necessarily unique across different routes.  When importing these features, we get duplicate shape_id errors on import as result.  The previous code avoided this problem because it just generated a unique shape_id for each shape.

My fix tries to maintain the best of both worlds.  We first try to import a shape with the element name as the shape_id.  If there is no existing shape with that id or if the existing shape has the same set of points, we are ok.  However, if there is a duplicate shape with different points, we modify the shape_id of the new shape to avoid conflicts.
Whitespace.