Add Scala collections support to jDBI

Permits a DAO to return:
  * `Option[A]`
  * `Set[A]`
  * `Seq[A]`

`Map[K, V]` is not permitted, as jDBI doesn't support deserializing in
to Maps.

Permits arguments of type:
  * `Option[A]` - Serializes `None` as an SQL `NULL`.