[tz] Reason for removal of several TZ abbreviations

[Garrett Wollman]

<<On Mon, 4 Dec 2017 23:02:39 -0500, Tim Parenti <tim at timtimeonline.com> said:

> Frankly, I've long thought the whole idea of fully-opaque IDs is a
> non-starter, and I'd much rather see our collective efforts spent
> elsewhere.  Time zones are inherently geopolitical in nature; we can
> certainly work to minimize the impact of geopolitics on this project, but
> we cannot eliminate it entirely, and efforts to do so are fruitless.

+1

-GAWollman