Add the Spanish translation

[aslozada]

Add the Spanish translation

Added items: es directory

*The buttons Browser <> without translation

Issue of design

• In title box: the responsive design fails, sometimes.

[awvwgk]

Awesome, thanks a lot.

Have a look at the headers for the po file, they contain an author field where you can add your name and contact, currently it is copied from the German translation and contains mine.