Article and live blog style tweaks

A bunch of style tweaks for Articles and Live Blogs. Some examples:

![article-4](https://f.cloud.github.com/assets/518943/1255395/9856ead2-2b84-11e3-9ae7-60a63ad8d356.png)
![article-3](https://f.cloud.github.com/assets/518943/1255396/98666516-2b84-11e3-8f89-f63ea55778a4.png)
![article-2](https://f.cloud.github.com/assets/518943/1255397/98787ddc-2b84-11e3-9931-4307945a7a93.png)
![article-1](https://f.cloud.github.com/assets/518943/1255403/ac514dac-2b84-11e3-9e36-f611ed819a32.png)