DATACMNS-310 - Prepare feature branch.
DATACMNS-310 - Integrated ChainedTransactionManager from Spring Data Neo4j.

We now integrate a best-effort PlatformTransactionManager that will propagate commits and rollbacks to all PlatformTransactionManager instances registered. This assumes that the exceptional cases which will cause a rollback to happen either before the commits or during the first commit.
DATACMNS-310 - Additional round of polish.