tag version 0.16; speed up
tag version 0.17; speed up dict loading
tag version 0.18; support keywords extraction
tag version 0.19; support user defined dictionary
tag version 0.20; support POS tagging
tag version 0.21; load_userdict accept file-like object
tag version 0.22; new API: jieba.cut_for_search
tag version 0.23; support ENG-CHN mix words
tag version 0.24; fix multiplication overflow; change to use sum of Log
tag version 0.25; traditiona Chinese
tag version 0.26; keep punctuation
tag version 0.27; parallel mode
tag version 0.28; lazy load
tag version 0.28.1; fix bug of file leak
tag version 0.28.3
tag version 0.28.4