WIP: Try to use RAT 0.18 - help needed with Maven project structure

[ottlinger]

Trying to add configuration for RAT 0.18, but the basic scan does not pass and reports many thousand new unlicensed files .... as I'm not sure about the Maven project layout I don't know where RAT is configured for the whole project.

Can you help out? @slachiewicz @slawekjaranowski

[cstamas]

The other day was tinkering with same problem, and we have issues as well:
https://issues.apache.org/jira/browse/RAT-567
https://issues.apache.org/jira/browse/RAT-554

Idea is that Maven POM should really not contain RAT config, merely a plugin definition with one liner config, that points to some sort of RAT config file, presumably in repository root. This way, that file would end up in source bundle as well, and could be picked up by tools like ATR is, as currently we have divergence between config used in build by Maven, ATR reports unrelated errors, etc.

[cstamas]

RAT plugin as I found, top to bottom:
ASF parent POM: https://github.com/apache/maven-apache-parent/blob/master/pom.xml
ASF Maven parent POM: https://github.com/apache/maven-parent/blob/master/pom.xml#L1280-L1311
ASF Maven project root POM: https://github.com/apache/maven/blob/master/pom.xml#L812-L835