* africa (Egypt): Prefer 24:00 to 23:00s, as 24:00 works nowadays.
* europe, northamerica: Update Willett URL.
* tz-link.htm, NEWS: jCal is now RFC 7265.  Mention PTP and the

draft CalDAV extension.  Update URLs for TSP, TZInfo, IATA.
Remove stale pointers to World Time Explorer and WORLDTIME.