A fully re-translated Simplified Chinese zh_CN lang pack. 

Original zh_CN langpack was just a converted version from zh_TW, changing traditional Chinese characters to simplified ones. 

Since China Mainland and Taiwan translates the same English word into different Chinese words, simply converting characters between traditional and simplified just DON'T WORK. A few examples:

> - "Hex number" (from validator hex), translated to "16位元碼" in Taiwan, can be converted to simplified character and get "16位元码". But in China Mainland we translate it to "16进制数". 
> - "Macro", translated to "巨集" in Taiwan, can be converted to simplified character and get "巨集". But in China Mainland we translate it to "宏" (even length are not the same! ). 
> - "Saudi Arabia" (from validator iban), translated to "沙烏地阿拉伯" in Taiwan, can be converted to simplified character and get "沙乌地阿拉伯". But in China Mainland we translate it to "沙特阿拉伯". (the intresting thing is: zh_TW langpack misused this China Mainland translation! )

CONCLUSION: Simplified Chinese (used in China Mainland) and Traditional Chinese (used in Taiwan) MUST be considered as DIFFERENT languages and translates respectively by local translators. 

I reviewed all the conversion made by @tureki, just discarded most of them and retranslated it to my own. 

Despite of all the translation differences, there are also various errors corrected in this commit. This is a complete summary: 

> - Mistranslated Switzerland(CH) to Sweden(SW). --- Their Chinese translations are similar. 
> - Misunderstood the meaning of "step" from `step.js`. --- Step (for wizard) and step (for numeric values) are 2 different words in Chinese.
> - Mistranslated country name "Jordan". --- Jordan (NBA star) and Jordan (country) are 2 different words in Chinese.
> - Mistranslated country name to language name for multiple countries. 

I hope these corrections can be backported to zh_TW by a Taiwan local translator in the future. (I just can't do it since I'm from China Mainland, sorry)

SHA Miao
from: Changchun, Jilin, China Mainland