[Twisted-Python] Deferred flow control examples

[Tristan Seligmann]

When trying to help people understand how to use
Deferred.add{Callback,Errback,Callbacks,Both} I've found it useful on
a number of occasions to illustrate flow control with Deferreds by
comparison with synchronous code. I realised there wasn't really
anyway that a "complete" set of examples was collected, so I wrote
this blog post:

http://mithrandi.net/blog/2011/06/flow-control-with-deferreds-by-example/

I'd appreciate it if people could take a moment to review the examples
(I think they're all correct, but maybe I made a mistake somewhere),
suggest any important examples I missed, and let me know if they find
this approach generally useful.
-- 
mithrandi, i Ainil en-Balandor, a faer Ambar