[pybsddb] Transactions

[Matt Chaput]

> However, I tried setting the cache to 4MB and that fixed the problem! Or at least masked the problem ;). It’s now roughly the same speed (slightly faster) as the object returned by bsddb3.btopen().

Oops, looked like a spoke too soon. Increasing the test to 5,000,000 keys resulted in the wrapper taking 93 seconds, while I stopped the transactions version after 25 minutes :(

Matt