title: Cut a polygon with two lines in Shapely
body: <p>I am trying to cut a <code>shapely.geometry.Polygon</code> instance in two parts with two lines. For example, in the code below, <code>polygon</code> is a ring and if we cut it with <code>line1</code> and <code>line2</code> we should get two partial rings, one w/ 270 degrees and one with 90 degrees. Would there be a clean way to do this?</p>
  
  <pre><code>from shapely.geometry import Point, LineString, Polygon
  
  polygon = Point(0, 0).buffer(2).difference(Point(0, 0).buffer(1))
  line1 = LineString([(0, 0), (3, 3)])
  line2 = LineString([(0, 0), (3, -3)])
  </code></pre>