Small css fix to break very long nonbreaking space (ie: added word break)

Very long posts were not word breaking properly.

Before:
![selection_001](https://f.cloud.github.com/assets/6403056/1937788/180d7d9a-7f31-11e3-938b-032c4fd67568.png)

After:
![selection_002](https://f.cloud.github.com/assets/6403056/1937789/1f5e957a-7f31-11e3-8064-9ba1bd1040c7.png)