master: So, rusty on JPA. Forgot it doesn't maintain both sides of bidirectional join mappings for you. Basically, it doesn't make sense to code it in JPA at all, versus just embedding the logic in the DAO layer. Done, and tests are revised and passing, although they still need more work.
master: Cleaned up file node tests. Need to look closer at exception expectation, but I think they are cleaned up now. Got some bad advice online about persistence ordering, fixed it.