-currently: working to address the instability of the Voronoi code relating to the radius of input sphere data (i.e., 2.0 works, 1.9999 doesn't; 87.0 doesn't, etc.)
-implemented the special case of the Vincenty formula described here: http://en.wikipedia.org/wiki/Great-circle_distance
-implemented unit tests for the above Vincenty code
-working to code in a switch that returns a theta value of 0 from calculate_and_sum_up_inner_sphere_surface_angles_Voronoi_polygon() when there is a problem with the calculation of inner angles (this should force planar polygon SA calculation in these cases)
-it is not clear that anything has improved as a result of switching to the Vincenty code