Add comment counts to news items on user pages

Comment counts don't currently display for the news stories on user pages. This adds comment_count to newsItems, just like on the home page.

![screen shot 2014-02-12 at 11 06 57 pm](https://f.cloud.github.com/assets/708882/2156930/c37cde1e-946c-11e3-8aed-4f50e07e8936.png)