Add language code for Vietnam

Official language is Vietnamese, ISO 639-1 code "vi" (http://en.wikipedia.org/wiki/Vietnamese_language)
Added language codes for Singapore

* English "en"
* Malay "ms"
* Tamil "ta"
* According to http://en.wikipedia.org/wiki/List_of_ISO_639-1_codes there are no code for Mandarin, added as "zh"
Added language codes for Brunei

* Malay "ms"
http://en.wikipedia.org/wiki/List_of_ISO_639-1_codes
Merge pull request #31 from ted451/master

Added some language codes data (thanks @ted451)