Write a Maven-based update site generator

[ctrueden]

A Maven-based update site generator could produce db.xml.gz files for artifacts available from a remote Maven repository. So e.g. we can generate an update site for Fiji by running the generator against sc.fiji:fiji. It would scrape the maven-metadata.xml for all release and snapshot versions of Fiji, and declare them in the db.xml.gz. It would declare the dependencies to match the declared deps of that GAV (need to check whether the Updater is smart enough regarding transitive deps, though—I'm guessing it is).

• For stable, use release versions only. For unstable, use the latest SNAPSHOT.
• There might be a problem with old snapshots disappearing: rerunning the generator after a snapshot has disappeared would (naively) make that version no longer declared in the db.xml.gz. But we can get around this by supporting unioning of existing db.xml.gz metadata with newly generated content.
• Because we have datestamps for all published Maven artifacts, we should be able to support downgrading in a future version of the Updater.

[imagesc-bot]

This issue has been mentioned on Image.sc Forum. There might be relevant details there:

https://forum.image.sc/t/omero-plugins-in-fiji-compatibility-with-imagej-omero/70248/2