Cerber Theme updates

New social button for Cerber Theme:

![social_buttons_new_login](https://f.cloud.github.com/assets/1256298/726146/f6f3db9e-e0d5-11e2-85da-61addecbb5c3.png)
![social_buttons_new_reg](https://f.cloud.github.com/assets/1256298/726147/f797ce8e-e0d5-11e2-9055-c1fd89c2284b.png)