Add a test that shows the problem.
Allow boolean-looking strings as well as number-looking.
Make the test more obvious.
merge mmcm: Although the recent change to expose AkBool included extensive new tests, they missed the simple case of boolean string literal, such as 'true', which was ending up as false.

https://code.launchpad.net/~mmcm/akiban-server/parse-boolean/+merge/155086