Making Plomino composable.
Related to #301 and #436.
Import a sub-database (let's call it a module) to add a defined unit of functionality to your database. For example, a developer can create a good db to handle configuration documents, or managing email templates and sending mail. Users can import such modules into their own db.
A module provides internal forms to document and configure it.
getParentDatabase does not find a module parent.