[tz] Reason for removal of several TZ abbreviations

[Guy Harris]

On Dec 4, 2017, at 8:16 PM, Michael Douglass <mikeadouglass at gmail.com> wrote:

> The names unfortunately are political - like it or not. Apparently there are organizations that cannot use this data for that reason. Using the current naming as an internal reference is fine but the timezones themselves should have an opaque id that doesn't cause problems. CLDR provides localization data - we just need a new key.

The CLDR provides localization data for timezone abbreviations (and timezone long names) in the <timeZoneNames> sections of main/{2-letter-language-code}.xml, in the list of <zone type="XXX"> and <metazone type="XXX"> items.  The XXX's for <zone> are tzdb region IDs, and if we changed the tzdb region IDs, those would have to change, but the XXX's for <metazone> aren't tzdb region IDs, and wouldn't have to change if we changed tzdb region IDs.