Ogm 521 natural one to one

https://hibernate.atlassian.net/browse/OGM-521

This patch will remove the redundant column created for *ToOne associations on nodes.
I add to add some metadata in the TupleContext to achieve this.
I'd more focus on what OGM is doing and not actually mention how it's not mapped: "The association from Husband to Wife will be mapped as a relationship in Neo4j. If required, the id of the associated Wife entity can be obtained by navigating to the related Wife node and reading its id."

Btw. the wrapping is a bit odd. Do you still stick to the "one thought per line" approach?