Sort users by nickname and fix style in list

# What's up

Given that we have more users, I was finding quite hard to find someone. This PR orders users by nickname. And fixes also a styling issue.

*Before*

![screen shot 2014-05-29 at 16 08 29](https://cloud.githubusercontent.com/assets/62895/3119095/1fa62f6e-e743-11e3-909c-c941f6d7aba5.png)

*After*

![screen shot 2014-05-29 at 16 08 13](https://cloud.githubusercontent.com/assets/62895/3119097/2351c18c-e743-11e3-872d-b8e679b2ff7e.png)