i2b2 sessions remain active after 30 minute inactivity threshold

1. Log in to an i2b2 project
2. Leave your browser alone for more than 30 minutes
3. Try to query in the i2b2 project

expected result: session timed out; query fails
actual result: query succeeds

I reported the problem and a fix in a 7 Sep message to members@i2b2aug.org

For the fix, see http://bitbucket.org/DanC/i2b2-pm-cas/changeset/f16e3c4f6757