[MERGE] Support for Putty SSH implementation, 2-nd edition

[John Arbash Meinel]

John Arbash Meinel has voted +1 (conditional).
Status is now: Conditionally approved
Comment:
Actually, you could use a Registry, since 'get(None)' is intended to 
return the 'default'. Versus get('value') which could return a specific 
vendor. And the default is key=None, so "Registry.get() is supposed to 
return the default."

I'm not going to be strict on it, since you seem to have at least 
conformed to a basic interface consistency with your implementation.

I would like to ask you to revert your whitespace changes to errors.py 
at least. Since that is already a likely place for text conflicts to 
occur. (Which is a shame, since I'd really like to see them fixed :)


For details, see: 
http://bundlebuggy.aaronbentley.com/request/%3C45E84FCB.8020000%40hlabs.spb.ru%3E