Schema version used when creating OME TIFF/XML

[rleigh]

This story is to track the issues relating to "bad" versions of the OME schemas being used when writing OME TIFF/XML files. In this context, "bad" means not an officially released version of the schema, which may result in problems at some future time where the file may not validate and/or be readable in general.

• FIJI has potentially provided development versions of bioformats in the past, using unreleased schema versions. It's not clear at present what the scope of exposure of end users is (i.e. when this happened, which versions of bioformats, and for how long)
• if a development version of the schema is used, there is no supported upgrade path to later schema versions; the file may become unreadable as the model changes over time (the generated code won't be able to read it, and it won't be automatically upgradeable to a version which could be processed)

While in general it would be a good idea for FIJI to not provide prerelease snapshots of bioformats, it would be good if we could take any possible steps in bioformats/omero to prevent and/or mitigate this if at all possible. This might, for example, mean ensuring there is a supported upgrade path for any schemas ever in use on develop and/or only ever using released versions on develop and restricting testing unreleased schemas on test branches (while also making sure FIJI or anyone else does not use these branches).

[jmoore]

A few notes from a discussion with Roger,

• Might be worth checking the apache logs for the use of any of the git-based specifications
• If possible, would be good to add a warning if a user ever tries to save with a git-based specification (though this might have to be sent back in a time-machine)
• Overall review the process of what versions of specs get pushed to users. Especially important for the EXPERIMENTAL jars from the merge builds. In general, anything from the ./InProgress directory could be treated like a Maven SNAPSHOT jar.

[jburel]

This will be handled by trello card
see ​https://trello.com/c/XXpnevzl/54-ome-xml-in-api