Wired up version listing. Other modules can now register script directories for SQL files which are executed against the database to incrementally build the required schema. Each successful run is logged in the database. For now, these are plain scripts. The plan is to allow for differentiating between various db engines, for example by recognizing file endings like .pgsql.sql, and maybe support PHP code that can utilize the Doctrine DBAL. Had a look at the Doctrine Migrations, but the docs only show how to manage the db versioning via the CLI. We will be running without console access, so that is not an option. Will take a look at the Migration sourcecode anyway, since we probably can reuse their classes. This will take more investigation, however.