Add english, german and pinyin translations

[rubo77]

also requested here: https://github.com/ACTom/kityminder-editor/pull/1

signed-off-by: Ruben Barkow github@r.z11.de

[ACTom]

这个PR的德语有问题，我合并之后做了一些修改。
另外，当前kityminder-editor的国际化并不完全，逻辑层代码、对话框都没有做国际化，不太建议合并这个pr。

[rubo77]

Could you please add the english translations in the german file then?

I cannot read any chinese, so I used Google translate to achieve this. if the english translation works, I can have a look over the german translation.

please someone take over this PR and finish it.

Thanks

[ACTom]

@rubo77 In my branch, you can continue to translate it, I have change default lang to English, and fix some English translate string.
PS: You can close this pr by yourself.