Increase width for download/upload speed tooltip

The hover tooltip needed to be wider to fit the Download/Upload speed information.

Old:
![screen shot 2014-04-23 at 13 41 29](https://cloud.githubusercontent.com/assets/2265702/2778372/70bf03e4-caf1-11e3-8987-0557d0420ed9.png)

New: 
![screen shot 2014-04-23 at 15 14 45](https://cloud.githubusercontent.com/assets/2265702/2778394/b47c18ec-caf1-11e3-8936-6668177ca9a7.png)