timezone data: update to 2018i

timezone data: update to 2018i

Update timezone data to 2018i

http://mm.icann.org/pipermail/tz-announce/2018-December/000053.html
http://mm.icann.org/pipermail/tz-announce/2018-December/000054.html

2018h:
* Qyzylorda, Kazakhstan moved from +06 to +05 on 2018-12-21.
* New zone Asia/Qostanay because Qostanay, Kazakhstan didn't move.
* Metlakatla, Alaska observes PST this winter only.
* Guess Morocco will continue to adjust clocks around Ramadan.
* Add predictions for Iran from 2038 through 2090.

2018i:
* São Tomé and Príncipe switches from +01 to +00 on 2019-01-01.

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