Breaking/migrate maven to plugin parameters

[buchananwill]

This PR combines the work I've done yesterday and today on both the Gradle and Maven plugins. The first half is a duplicate of the other pull request which is only the Gradle plugin. I've done this so you can view the entire proposal in context. I don't mind if you want to accept the smaller PR first (or only), and address the Maven aspect separately. However I think it makes more sense to see the changes as a whole, which really comprises three stages:

1. Add Gradle plugin
2. Pull the parameters into the core module without breaking the Gradle plugin
3. Replace the matching parameters from the Maven plugin with the shared class now available from the Core module.

Also, I didn't like the idea of pre-empting the version bump as that's totally your prerogative as repo owner, but it seemed like the safest way to ensure that I wasn't testing stale caches in the dependent modules. I won't be offended if you want to take a different tack or increment differently.