The python wrappers used to call each overloaded method in turn until
one of them was able to resolve the arguments.  A new method has been
added to vtkPythonUtil.cxx called PyVTKCallOverloadedMethod() that will
carefully check the overloads against the provided arguments.  Overloads
that have a perfect type-match to the args get first priorty, followed
by trivial conversions like "int" to "short" or resolving a VTK subclass,
followed finally by more advanced conversions like "float" to "int".