Message2911

I have modified the code according to your comments. 

1) In CPython, dict and subtypes of dict can be comparable. So I need to change
   in PyDictionary. There were two implementations for __eq__ and __cmp__.
   I made it one. The __eq__ and __ne__ will be using __cmp__ function.

2) There is no need of change in PyException. I reverted it to old code.

3) default_factory's access is private now.

4) In __missing__ method, default_factory.__call__() is used instead of 
   eval function.

5) I removed __copy__ function.

File Added: new_collections_one.diff