Before this feature was built to ST2, you might want to try the ConvertToUTF8 plugin. It supports for editing and saving files with CJK encodings include GBK, BIG5, EUC_KR, Shift_JIS, etc. See https://github.com/seanliang/ConvertToUTF8 for more information. 

Please take a look at this plug-in which supports editing and saving files with CJK encodings including EUC-KR: https://github.com/seanliang/ConvertToUTF8

Please take a look at this plug-in for GB2312, GBK, BIG5 and other CJK encodings: https://github.com/seanliang/ConvertToUTF8 

Please take a look at this plug-in for GB2312, GBK, BIG5 and other CJK encodings: https://github.com/seanliang/ConvertToUTF8