Correct times for Asia/Taipei before 1945-10-25.

(Thanks to Yu-Cheng Chuang.)  Also, update time zone abbreviations for
Japan's two time zones used 1896-1937.  JWST now stands for Western
Standard Time, and JCST for Central Standard Time (formerly this was CJT).
* asia (Taiwan): Omit DST during 1945.
(Asia/Taipei): Add a transition to JWST on 1896-01-01, then to
JST on 1937-10-01, then to CST on 1945-10-25.
(Asia/Tokyo): Rename CJT to JCST.  Transition to JCST was 1937-10-01,
not 1938.
(Asia/Seoul, Asia/Pyongyang): Call UT+9 "JCST" until 1937-01-01,
"JST" thereafter.  Assume JCST/JST until Allied takeover after WWII.
* NEWS: Document this.