Actually order when paginating, with no args it's a no-op

@yzhangmedidata The call to `.order` [doesn't actually do anything with no args in Rails 3](http://apidock.com/rails/v3.2.13/ActiveRecord/QueryMethods/order). We missed this for a while because MySQL usually returns items in ascending order by id anyway. But when it's using a different index, the order becomes non-deterministic, which obviously is unacceptable when paginating. `order(:id)` solves the problem.

Specs pass, except for the Neo ones that were already broken.