Open in default browser button

I added a little button so that the user can open an article in their default browser. nothing major but I think it can be frustrating not being able to easily access the article in my own browser if I need to for some reason. It's just a little browser icon.

![device-2013-04-06-173742](https://f.cloud.github.com/assets/1024060/347538/6e54797c-9ed8-11e2-9af9-9c4522898b4b.png)