I added a Movies demo, using a Soil database. There was a previous Accounting demo that had two versions (in memory database and Soil database) from which I based the new demo. I like the Movie demo because it is simple yet complex enough. I suspect the Accounting demo is too complicated to grasp as a first encounter. I���m going to use the Movie demo for a presentation, so it���ll continue to be tweaked. Mainly, I���ll be adding a way to use SoilTransaction with #commit, instead of #checkpointAndContinue.