Calendar Invite ICS Generator

Generate an iCalendar invite for an event we own. It should add, update, and cancel cleanly in common clients. EVENT Title, start, end, timezone: [FIELDS] Organizer: [EMAIL] Attendee: [EMAIL] Location or URL: [WHICH] UID stability: [THE EVENT ID IN OUR DB] DELIVER 1) The VEVENT fields: UID, DTSTAMP, DTSTART with TZID or UTC and why you chose it, SEQUENCE, and STATUS. 2) A create, an update (same UID, higher SEQUENCE), and a cancel (METHOD:CANCEL). Say what breaks if we mint a new UID on every edit. 3) The email part: text/calendar attachment and the content type parameters clients expect. A plain-text body so the email still makes sense. 4) Escaping: commas, semicolons, and newlines in the title. A test for a title with a comma. 5) Time zones: a note that a floating local time is the bug we are avoiding for a multi-zone audience. Do not promise a feature the ICS spec will not give us (a guaranteed accept). Do not include a private notes field in the invite.