Removed reference to the out-of-date (and not very useful) Objects/xxobject.c example.
Removed reference to the out-of-date (and not very useful)
Objects/xxobject.c example.

Updated the discussion of type checking to refer to
PyObject_TypeCheck.

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator