(a) added im_workflow__assign_to_vacation_replacement_if, (b) modified im_workflow__assign_to_supervisor to call the vacation replacement assignment pl/pgsql function as the task description dictated but also modified im_workflow__assign_to_absence_supervisor, (c) fixed im_workflow__assign_to_absence_supervisor in workflow-vacation_approval_wf-create.sql, (d) created upgrade script (not sure if the versions are right though), (e) slightly improved formatting in the aforementioned pl/pgsql functions