Orphan interface work through active admin

part of PT story https://www.pivotaltracker.com/story/show/76239618
    - added form with all fields for orphan and all field for addresses
    - index view
    - show view does not show address information yet
    - new migration that drops key fields in orphan and puts them in address
      so an orphan now has_one address rather than belongs to address for
      current and original addresses
    - migration has been built with extra information to make it reversible
    - changes orphan_spec to model change in relationship between orphan and
      address