Added mouse sensitivity setting to pause menu.

![mousesens2](https://f.cloud.github.com/assets/41687/846955/528b51a8-f42c-11e2-8dea-9460b83d1e1e.png)
![mousesens1](https://f.cloud.github.com/assets/41687/846957/67bc1a3a-f42c-11e2-8837-eea0b63afe59.png)