[Spambayes] database corruption

[Mark Hammond]

> Just to let folk know that the database corruption that I reported and
> filed a while back has happened again (#699063).

How about we do a db sync after we perform a train?  This shouldn't be too
painful, won't affect scoring performance, and should always leave the DB
consistent.  Only drawback I see is that after a huge retrain, my fast
machine takes a number of seconds to save the DB - OTOH, paying this penalty
*during* the retrain operation is moer appealing than paying it at shutdown
anyway.

Mark.