Truncate long words in Github issue feed with ellipses

Before:

![screen shot 2014-09-29 at 5 08 19 pm](https://cloud.githubusercontent.com/assets/1328849/4449784/d62eebe0-481e-11e4-8de4-a9566ea537e1.png)

After:

![screen shot 2014-09-29 at 5 10 44 pm](https://cloud.githubusercontent.com/assets/1328849/4449790/da634ad0-481e-11e4-8fa8-474d7bfe858e.png)