Remove test setup that is no longer used anywhere.

This was causing transient failures in the unit tests, because the
preference setting was hanging around after the unit tests had finished.
Since it's not used anyway, we might as well zap it.
Modify subject unit test to allow it to pass when run in isolation
Fix bug in directional relationships caused by the Array() method.

We were assuming that Array({:some => :thing}) would give:

  [{:some => :thing}]

but it actually gives

  [[:some, :thing]]

Fixed by porting the ActiveSupport "wrap" method into ASUtils and using
that instead.
Modify EAD export test to make it pass in isolation
Merge pull request #119 from marktriggs/directional-relationship-bugfix

Directional relationship bugfix