Adds new themes

Adds the themes:

* **default dark** ([preview](http://jsbin.com/uhagaw/3)): based in default theme.
* **black beauty** ([preview](http://jsbin.com/efujux/22)): inspired by *default dark*, it is resposive ([watch](http://mattkersley.com/responsive/?http://jsbin.com/efujux/22/quiet)).

Updates **user/evertton.json**.