title: Label regions separated by sharp edges
body: <p>Dear users and developers,</p>
  <p>I would like to label the regions of the surface of a 3D mesh based on the detected sharp edges. As a simple example, if we would have a cube, elements would get a different label for each of the six faces of the cube. Is there a way to accomplish this in CGAL?</p>
  <p>I am using make_mesh_3 to mesh the objects in question and using detect_features to ensure sharp edges are preserved during meshing.</p>
  <p>Regards, Tim</p>