Update timezone code from tzcode 2013i

[Ondřej Bílka]

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.