Fixed bug where user actions were enabled when a user was not selected.

This PR fixes user actions being enabled when a user has yet to be selected. This could happen directly after a user connects or disconnects to or from a server. The results of this PR can be visualized below:

Before  | After
------------- | -------------
![Before patch](https://cloud.githubusercontent.com/assets/110883/2625303/26fdb812-bd8c-11e3-8bc5-31bc3906b55a.png)  | ![After patch](https://cloud.githubusercontent.com/assets/110883/2625302/26fd3432-bd8c-11e3-881a-2646ddaea7da.png)