Extension to tzcode to support additional timezones

[lennox at cs.columbia.edu]

On Wednesday, October 27 2010, "Christos Zoulas" wrote to "tz at lecserver.nci.nih.gov, tz at elsie.nci.nih.gov, jhb at freebsd.org" saying:

> The second part of the discussion
> is how to deal with tm_zone. Do we document that if you tzfree() you are
> going to lose, or do we make it work using a string pool and thread locks?
> Or something else?

Remember that this means not only tm_zone per se, but also strftime("%Z"),
on systems which have tm_zone.

(On systems without tm_zone, as far as I can tell there's no way to get
strftime("%Z") correct for non-standard timezones, unless I'm overlooking
something.)

-- 
Jonathan Lennox
lennox at cs.columbia.edu