Add language variable for multilingual sites

[goanpeca]

See https://help.disqus.com/customer/portal/articles/466249-multi-lingual-websites

Language overrides

Using the this.language JavaScript variable, you can dynamically load the Disqus embed in different languages on a per-page basis. For example, to load the embed in Russian:

var disqus_config = function () { 
  this.language = "ru";
};

For a full list of language codes, see Languages on Transifex. Note however that Disqus does not support all languages offered in Transifex. For a full list of supported languages, see the Disqus project on Transifex.

[ikus060]

+1 here

Would be nice to have it integrated into the plugins directly.

[miratcan]

+1