Use semver-ignore configuration in update-versions maven goal

[metlos]

The update-versions maven goal uses hardcoded semantics to determine the required version update. All breaking changes require major version increase, non-breaking and potentially-breaking changes require a minor version increase and patch version is only ever increased in 0.x.y on non-breaking or potentially-breaking.

With the more advanced logic available in the semver-ignore extension, this is clearly insufficient.

Funnily enough the update-versions goal disallows the semver-ignore extension during analysis (for obvious reasons), but it should be clever enough to read its configuration. This will require some trickery during the revapi instantiation to read the full config first, extract what we need and only then proceed with disallowing extensions.

When at it, it would be nice to disallow extensions by their extension id, not by their class names.