forked from phoedos/pmd

This is kind of a [BOM](https://maven.apache.org/guides/introduction/introduction-to-dependency-mechanism.html#bill-of-materials-bom-poms), but different: It defines hard dependencies and not just versions for dependencyManagement. This new module depends on all languages modules and is used by pmd-cli and by pmd-dist. So, we have only one place to modify, when we add new language modules.