Py_Initialize(): Now that standard exceptions are builtin, we don't

need two phase init or fini of the builtin module.  Change the call of
_PyBuiltin_Init_1() to _PyBuiltin_Init().  Add a call to
init_exceptions().

Py_Finalize(): Don't call _PyBuiltin_Fini_1().  Instead call
fini_exceptions() but move this to before the thread state is
cleared.