Fix width of text in milestone lists and add assignee icon to merge requests.

Before:

![Screen_Shot_2015-03-06_at_13.48.00](https://dev.gitlab.org/gitlab/gitlabhq/uploads/5754638a3ebb79dee1f6c07a6e268035/Screen_Shot_2015-03-06_at_13.48.00.png)

After:

![Screen_Shot_2015-03-06_at_13.48.14](https://dev.gitlab.org/gitlab/gitlabhq/uploads/fe92adf387964efb3d460dfc61ced3b8/Screen_Shot_2015-03-06_at_13.48.14.png)

I've checked with other screen widths as well, and it looks good all the time.

See merge request !1645