Investigate versioning of phenopacket instances due to evolution in representation and disease progression

[jmcmurry]

There are two types of versioning we need to consider: representational and temporal.

1) Representational

Evolution due to change in ontology or scientific understanding. (Perhaps even to correct an error.)

2) Temporal

Evolution of sequential observations over time in a given patient/cohort/organism.

In both cases, we need a way to uniquely reference a specific version of a phenopacket instance, while being able to trace its history. This may have implications for the phenopacket registry more broadly. Long-tail repos like Dryad, Zenodo, etc are great at issuing DOIs but currently not up to that challenge of exposing versions in a sensible way. I love the way that F1000 displays/handles versioning. We should aim for that with the temporal considerations somehow woven in.