PREVIEW OGM 4.3 and 4.2 compatibility

Most commits are reorganized and potential candidates for inclusion anyway, but:

 - the last commit is questionable, but look at the cleanup it brings!
 - (better tested removing the last commit) you can see it fails the EAP integration tests: Class def not found

Note that if you replace Hibernate ORM 4.3.0.Beta3 version with 4.3.0-SNAPSHOT there are additional failures.