Add XING Social Icon

Hi BlueOwl!

We’d love to use the XING Icon within the template. XING is a business social network mainly in the german speakging regions with around 7 million members – just the same as LinkedIn for the German market.

I’d be happy to use the XING Icon in the theme options as well as for persons.

Any chance to have this implemented?

http://fortawesome.github.io/Font-Awesome/icon/xing/

http://fortawesome.github.io/Font-Awesome/icon/xing-square/

Thanks!