tzdata; 2016j -> 2017c

Notable recent changes:

 - Northern Cyprus resumed EU rules starting 2017-10-29.
 - Namibia will switch from +01 with DST to +02 all year, affecting
   UT offsets starting 2018-04-01.
 - Sudan will switch from +03 to +02 on 2017-11-01.
 - Tonga will not observe DST on 2017-11-05.
 - Turks & Caicos will switch from -04 all year to -05 with US DST,
   affecting UT offset starting 2018-11-04.