This operation moves a Member forward in the funnel by saving the next step.
Note that the step is by default only saved (and any triggers executed) if the Member is new to the Funnel or if the Step is higher
than the Member's current position in the Funnel. Otherwise the call is simply ignored.
This behaviour can be overridden by specifying the saveOld=true attribute, in which case older steps will be saved as well (if they don't already exist).
Note that triggers are not executed if an older step is saved.