[SAC] bayes spam filter was not working, now fixed

[Sandro Santilli]

I found out that all the bayes training was having no effect
after looking at the actual database tables. Enabling DEBUG
level logging I found the spambayes module was missing (dunno
why it wasn't printed to INFO or WARNING).

Installing spambayes (pip install) fixed the issue, so now
your spam training will actually _do_ something. It'll take
25 ham and spam entries before it's used to score submissions.

--strk;