[hibernate-dev] [OGM] More info for Cassandra and MongoDB datastores and dialects

[Emmanuel Bernard]

Hi all and in particular people developing around Cassandra ad MongoDB datastore / dialect.

I have been working on two things lately

## Expose table and column information to the `DatastoreProvider`

This is useful to build the right buckets in some NoSQL engines. In particular Cassandra can now use 
specific tables instead of the generic one we are using currently.
Let me know how it works.

## Expose infos on collection of embedded to `AssociationKey`

One thing I want out of the MongoDB Dialect is the ability to store collections of embeddable within the entity document itself instead of in a different document. I have added a couple of information to `AssociationKey` in that effect:

- the collection role
- the owner's entity key
- the type of association

To the MongoDB writers, let me know if the information is useful and if you can store collections of embeddable within the entity document itself.

I am especially unsure that the second point is enough so I would need testing.

Please comment on the pull request. https://github.com/hibernate/hibernate-ogm/pull/58

Emmanuel