Cn doc

Hi, this is all the translated *.po files you need.

As to Chinese user, they need to change the value of "language" in docs/conf.py if they want to generate pdf doc.

Assuming they have xetex and "WenQuanYi Micro Hei" font installed, add this to conf.py

latex_preamble = '\usepackage{xeCJK}\n\setCJKmainfont{WenQuanYi Micro Hei}'