Don't attempt to run tooling API build actions against Gradle versions that don't support it.
Ship the client's build action across to the provider.
Added a (rough) mechanism for plugins to contribute global services.
Changed the tooling API provider so that it runs an action in the daemon when the client provides a build action. Doesn't run the provided action, just runs a dummy for now.
Moved class from main to test source dir, as it is only used by tests now.
Some javadocs.
Removed some unused mocks.
Moved the various scope service registries to live together in a package.
Added @Nullable in a few places.
Moved another registry to live with the others.
Some renames.