Update timezone code from tzcode 2013i

[Paul Eggert]

Ondřej Bílka wrote:
> On Thu, Dec 19, 2013 at 04:56:07PM +0000, Joseph S. Myers wrote:
>> Now we have Paul's support for version-3 tz files checked in, this
>> patch updates all the code we take (unmodified) from tzcode to version
>> 2013i (which includes the support for generating version-3 tz files
>> where necessary).
>>
>> Tested x86_64.
>>
> Looks ok.

I'd say "looks ok" too, except that I wrote those tzcode
updates so I'm biased....