Require 'yaml'.
Merged r11483 from trunk to 2.3-stable (#13281)
Russian translation updated by Kirill Bezrukov.
Merged r11482 from trunk to 2.3-stable (#13280)
German translation changed by Filou Centrinov.
Russian translation updated by Kirill Bezrukov (#13281)
German translation changed by Filou Centrinov (#13280)
Merged r11476 from trunk to 2.3-stable (#13246)
Traditional Chinese translation updated by ChunChang Lo (#13279)
Russian translation updated by Filou Centrinov (#13266)
German translation updated by Filou Centrinov (#13265)
Bulgarian translation updated by Ivan Cenov (#13264)