Translation of language names

[verglor]

I think language names should not be translated - all should be always in it's language so everyone will find his language easier.
It will be much easier to maintain and faster to translate.
Also there's no point repeating credits in each translation file...

[daviddallet]

Hi,

I fixed some language names in French in my pull request yesterday, but I could +1 with your idea ;)

Easier for visitors and easier to code&maintain...