Replace some zones with links when that doesn't lose useful info.

This is like the 2013-09-02 change, but for the Pacific this time.
* antarctica (Antarctica/DumontDUrville):
* australasia (Pacific/Tahiti, Pacific/Saipan, Pacific/Majuro)
(Pacific/Chuuk, Pacific/Pohnpei, Pacific/Palau, Pacific/Funafuti)
(Pacific/Midway, Pacific/Wake, Pacific/Wallis):
Remove zone, replacing each with a link to a region that has had
the same UTC offset since 1970.  This removes data that were
largely invented, either by us or almost surely by Shanks or his
sources.
* asia, australasia, northamerica: Create links accordingly.
* NEWS: Document this.