> Er - while reverting it makes the code work again, I'm
> _really_ unhappy with this as a long-term solution.

I've addressed almost everything that's discussed here in issue 2849, 
implementing Josh's suggestion of using FeedParser.

It removes rfc822 (but not mimetools [yet]) dependency from the cgi 
module, without the parsing problem pointed by cgibug.py and without 
hanging, as shown in server.py + post.html. Also, preliminary tests 
revealed that the new FieldStorage.read_multi is about 10 times faster 
than the old one.