Better scss

Fixes #27 #22 

- Adds reset for comment elements
- Works on more themes
- Adds option for how the article should be modified

For layouts that have full width content, this might be a better option for modification of the article:
![ghost-push-casper](https://cloud.githubusercontent.com/assets/1572205/2867436/6f3025e8-d236-11e3-9884-b32fb08aa42d.gif)