consider versioning

[josemalonso]

Not intended for this phase of the project but we should carefully consider versioning in the future, also as part of the metadata. This would offer a greater granularity and flexibility (e.g. I'm thinking of a platform offering incremental downloads but also of an intermediary who can more easily build a service spotting shat has changed, what's new)
Current "downloads" would become versions.
Versioning needs more thought than this alone though.