Predicted new comment number is hard to recognize visually

Advances on #189

The predicted new comment number is super helpful.

However, it appears in a different spot than the numbers of existing comments, so my brain always needs an additional cycle to remember where it is located + recognize it.

For now, I'd like to propose to quickly fix the recognition problem only by making it appear in bold:

![dreditor-new-comment-number](https://cloud.githubusercontent.com/assets/41992/3152161/935bf6c4-ea8a-11e3-98b3-f60012953353.png)