Configuration files are too complicated, allow inclusion of shared configuration definitions.

[adixon]

There's a fair amount of duplication and complexity in the json configuration files, maybe we could have some kind of abstraction via extra configuration files, that combine and name common shared sets.

For example, for CiviCRM file backups, it'd be nice to combine the collection of configurations that determine which directories the files live in and the exclusions, so that I can reuse that collection across multiple configuration files and modify it in a single place.