Events violate the Eiffel specification

[magnusbaeck]

Description

The Eiffel events produced by this library don't follow the Eiffel specification. While they're syntactically correct and pass the schema validation they have various issues:

• The data.gitIdentifier.commitId field contains the change id instead of the commit id. The spec says that this field should contain "the commit identity (hash) of the change", and the change id doesn't fit that bill (e.g. because it isn't unique).
• The data.gitIdentifier.repoUri field contains the URL of the Gerrit change, e.g. https://gerrit.example.com/c/name/of/repo/+/123456. The spec says that this field should contain "the URI of the repository containing the change", i.e. something you can give to a git clone command.
• The meta.source fields are abused to include the change URL and the name of the change uploader.

Motivation

The produced events should follow the specification. I think the spec contains some ambiguities in the descriptions of the data.gitIdentifier fields but the things reported here shouldn't be controversial.

Possible Drawbacks

Changing this should be considered a backwards-incompatible change.