(a) added __update pl/pgsql function updating the event registration info of a given participant (work in progress), (b) now using person__name() as opposed to concatenating the columns from the persons table all over the code, (c) project_id is now required and enforced in registration.tcl and participants-list.tcl, (d) introduced flyhh_match_name_email tcl proc that is used to extract name and email from the partner and roommate values when inserting new participants or updating old ones