Rewrote the docs for supporting cyclic garbage collection to reflect

the new way that once writes types.

Deleted the old section and sample code and added a new section
building on the Noddy example.

Doc/ext/test.py

@@ -106,6 +106,99 @@ Traceback (most recent call last):
 TypeError: an integer is required
 >>> del n1
 >>> del n2
+
+Noddy 4
+
+>>> import noddy4
+>>> n1 = noddy4.Noddy('jim', 'fulton', 42)
+>>> n1.first
+'jim'
+>>> n1.last
+'fulton'
+>>> n1.number
+42
+>>> n1.name()
+'jim fulton'
+>>> n1.first = 'will'
+>>> n1.name()
+'will fulton'
+>>> n1.last = 'tell'
+>>> n1.name()
+'will tell'
+>>> del n1.first
+>>> n1.name()
+Traceback (most recent call last):
+...
+AttributeError: first
+>>> n1.first
+Traceback (most recent call last):
+...
+AttributeError: first
+>>> n1.first = 'drew'
+>>> n1.first
+'drew'
+>>> del n1.number
+Traceback (most recent call last):
+...
+TypeError: can't delete numeric/char attribute
+>>> n1.number=2
+>>> n1.number
+2
+>>> n1.first = 42
+>>> n1.name()
+'42 tell'
+>>> n2 = noddy4.Noddy()
+>>> n2 = noddy4.Noddy()
+>>> n2 = noddy4.Noddy()
+>>> n2 = noddy4.Noddy()
+>>> n2.name()
+' '
+>>> n2.first
+''
+>>> n2.last
+''
+>>> del n2.first
+>>> n2.first
+Traceback (most recent call last):
+...
+AttributeError: first
+>>> n2.first
+Traceback (most recent call last):
+...
+AttributeError: first
+>>> n2.name()
+Traceback (most recent call last):
+  File "<stdin>", line 1, in ?
+AttributeError: first
+>>> n2.number
+0
+>>> n3 = noddy4.Noddy('jim', 'fulton', 'waaa')
+Traceback (most recent call last):
+  File "<stdin>", line 1, in ?
+TypeError: an integer is required
+
+
+Test cyclic gc(?)
+
+>>> import gc
+>>> gc.disable()
+
+>>> x = []
+>>> l = [x]
+>>> n2.first = l
+>>> n2.first
+[[]]
+>>> l.append(n2)
+>>> del l
+>>> del n1
+>>> del n2
+>>> sys.getrefcount(x)
+3
+>>> ignore = gc.collect()
+>>> sys.getrefcount(x)
+2
+
+>>> gc.enable()
 """
 
 import os