(tz) Support tzdata2016a

The 2016a release of the tz code and data is available. It reflects the
following changes, which were either circulated on the tz mailing list
or are relatively minor technical or administrative changes:

   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.

   Changes affecting past time stamps

     Asia/Karachi's two transition times in 2002 were off by a minute.
     (Thanks to Matt Johnson.)

   Changes affecting build procedure

     An installer can now combine leap seconds with use of the backzone
file,
     e.g., with 'make PACKRATDATA=backzone REDO=posix_right zones'.
     The old 'make posix_packrat' rule is now marked as obsolescent.
     (Thanks to Ian Abbott for an initial implementation.)

   Changes affecting documentation and commentary

     A new file LICENSE makes it easier to see that the code and data
     are mostly public-domain. (Thanks to James Knight.) The three
     non-public-domain files now use the current (3-clause) BSD license
     instead of older versions of that license.

     tz-link.htm mentions the BDE library (thanks to Andrew Paprocki),
     CCTZ (thanks to Tim Parenti), TimeJones.com, and has a new section
     on editing tz source files (with a mention of Sublime zoneinfo,
     thanks to Gilmore Davidson).

     The Theory and asia files now mention the 2015 book "The Global
     Transformation of Time, 1870-1950", and cite a couple of reviews.

     The America/Chicago entry now documents the informal use of US
     central time in Fort Pierre, South Dakota. (Thanks to Rick
     McDermid, Matt Johnson, and Steve Jones.)

Here are links to the release files:

   ftp://ftp.iana.org/tz/releases/tzcode2016a.tar.gz
   ftp://ftp.iana.org/tz/releases/tzdata2016a.tar.gz

The files are also available via HTTP as follows:

http://www.iana.org/time-zones/repository/releases/tzcode2016a.tar.gz
http://www.iana.org/time-zones/repository/releases/tzdata2016a.tar.gz