Ported most of old Ef5 model-first Dal code to the new EfCodeFirst (ef6) Dal.

* Moved over the Dals and the ContextManager.
* I think it's ready for testing...probably will bomb!
* I made a lot of on-the-fly changes that I think were relatively correct,
  but who knows...that's what unit testing is for.

Signed-off-by: William Raiford <bill.mybiz@gmail.com>