How could we reliable inject owl:priorVersion into a release file?

Given that not all ontologies that are release are actually present in the repo, this would only work if there was a way to obtain the latest release string somehow from our purl system? @balhoff

Start by tracing how release files are generated and how the purl system exposes the latest release string. Confirm how ontologies absent from the repository are represented, then define what reliable owl:priorVersion injection would mean for those releases. Done means the approach works for both repository-present and externally released ontologies.

Written by the indexing model from the issue text.