timezone data: update to 2016a

timezone data: update to 2016a

Update timezone data to 2016a.

http://mm.icann.org/pipermail/tz-announce/2016-January/000035.html

   Changes affecting future time stamps

     America/Cayman will not observe daylight saving this year after all.
     Revert our guess that it would.  (Thanks to Matt Johnson.)

     Asia/Chita switches from +0800 to +0900 on 2016-03-27 at 02:00.
     (Thanks to Alexander Krivenyshev.)

     Asia/Tehran now has DST predictions for the year 2038 and later,
     to be March 21 00:00 to September 21 00:00.  This is likely better
     than predicting no DST, albeit off by a day every now and then.

   Changes affecting past and future time stamps

     America/Metlakatla switched from PST all year to AKST/AKDT on
     2015-11-01 at 02:00.  (Thanks to Steffen Thorsen.)

     America/Santa_Isabel has been removed, and replaced with a
     backward compatibility link to America/Tijuana.  Its contents were
     apparently based on a misreading of Mexican legislation.

Signed-off-by: Hannu Nyman <hannu.nyman@iki.fi>