Add SpamBayes performance test (issue179110)

[Skip Montanaro]

(Not sure how I'm supposed to make this known to people other than Collin.
Passing it along. Is there some protocol for alerting people to new reviews?)

Reviewers: collinwinter,

Message:
PTAL

Description:
Here is a straightforward performance test using the SpamBayes tokenizer
and its scoring machinery. This is my first attempt at writing a
performance test so I'm a bit unclear on how much priming of the pump is
needed.

Please review this at http://codereview.appspot.com/179110

Affected files:
M perf.py
A performance/spambayes/bm_spambayes.py
A performance/spambayes/hammie.pkl
A performance/spambayes/mailbox

[col...@gmail.com]

Committed as
http://code.google.com/p/unladen-swallow/source/detail?r=945

I reduced the amount of pump-priming because I think the the lower
amount is a fairer test.

Thanks, Skip!

http://codereview.appspot.com/179110