Add support for person.cars.all(:offset => "id1-", :limit => 4) when foreign keys are persisted in owner.

[thhermansen]

In a references many relationship where the target's foreign keys are persisted in the owner and you try to do a person.cars.all(:limit => 1, :offset => "something") some of these options are unsupported. The reason for these being unsupported is that we have to implement offset and limitiation in pure Ruby working on that car_ids array in the person. Its nothing close to impossible; it just has not been done yet.

We need to work on the foreign keys array, sort it and ensure that the ids from before the offset are sliced off. We'll also need to limit the array and manipulate keys in any other ways which the options dictates. This is not a problem if cars where using the :records_starts_from option (not persisting foreign keys in proxy owner), as then it's up to hbase to do the offset and limitation etc.