Resolves: #1574758
Rebase to tzdata-2018e
- North Korea changed from UTC+8:30 to UTC+9 on May 5, 2018.
- In this update, the upstream project now defaults to using
the "vanguard" data implementation which includes negative DST offsets.
However, we are continuing to provide the "rearguard" format
for data which does not use negative DST offsets to provide
better compatibility with existing tools. We intend to transition
to the "vanguard" data implementation in the future.