Anorm unsafe None

Historically Anorm passes `None` as JDBC parameter using `.setObject(x, null)`. That's unsafe and causing issues (e.g. http://stackoverflow.com/questions/26798371/anorm-play-scala-and-postgresql-dynamic-sql-clause-not-working ).
FYI, instead of `(None: Option[DateTime])` you can use `Option.empty[DateTime]`.