Allows "walking" of a table of ActiveRecord records by implementing #next_record and #previous_record. Options: - field: [Defaults to 'id'] which field should be used to calculate order. If two records have the same value for the specified field, records will be sub-ordered by ID. - cycle: [Defaults to false] upon reaching last (or first) record in order, determines whether or not it should return nil or cycle to beginning (or end) - filters: [Defaults to {}] a hash passed to self.class.where to determine scope. This will break if the ActiveRecord object does not have all of the keys that are passed into the hash.