* europe: Add dates for historical use of FET.
* europe (Europe/Minsk): Change abbreviation from FET to MSK

when Moscow changes it clocks (2014-10-26 01:00 Minsk time).
* NEWS: Document this.
* backzone (Asia/Hanoi): New entry.

(Asia/Phnom_Penh, Asia/Vientiane): Update to be consistent.