JDF-412 get jdf repo modifications

Before moving JDG to git submodule, we need to get all modifications from JDF repo. This modifications are present in this PR.

- The readme path was updated to consider the git submodule folder (one more lever).
- The header and source code format (some files) was updated to match https://github.com/jboss-jdf/jboss-as-quickstart/blob/master/CONTRIBUTING.md
- The properties was updated to match https://docspace.corp.redhat.com/docs/DOC-135368
- The version were also update to 6.1.0 which is the latest JDG version. (focus on products)