Continue with Repository to match Rugged's API.

* Add .DS_Store to .gitignore
* Add reverse mappings for OType and StatusCode
* Correct Oid to use an underlying struct.
* Try to fix Config.foreach
* Add basis of an OdbObject
* Use boolean natively instead of mapping it to an int (JNA does that)
* Cleanup Repository slightly and add:
** Status
** Ids/EachIds
** Contains
** MergeBase
** Read/Write
** Clone
** Hash/HashFile
** Make odb a lazy val and flatMap against it
* Test: Refactor File deletion into a helper.
* Test: Add beginnings of a TestRepository mixin to work
  against an fixed Repo.