Too much console logging during test suite

The new logging regime in 1.0 is much better for operational use, but not as nice for the test suite. When errors occur during the run of the state machine (even if they're properly caught and ignored), you'll get the output on the console.

Unfortunately, unittest doesn't have any good way to package-fixture the test suite, which is where we'd normally set the logging level lower for console output during the test run. Nose does, but I'm not sure it's worth adding that dependency.

Oh, and see http://bugs.python.org/issue16662 for why the obvious unittest hack doesn't work. :(