Made the data argument in Point's __init__method to be an optional argument by making it a boost::python::optional.
#ifndef __PYTHON_BIRTHID_H__
#define __PYTHON_BIRTHID_H__
#include <boost/python.hpp>
namespace dionysus {
namespace python {
//typedef int BirthID;
//typedef boost::python::long_ BirthID;
typedef boost::python::object BirthID;
} } // namespace dionysus::python
#endif // __PYTHON_BIRTHID_H__