Adding styling and implementation fixes for vertical volume menu

Previous implementation wasn't completely correct; styling was
out-of-date. Addresses #942

example to play with here: http://codepen.io/jnwng/pen/peDhl

![screen shot 2014-04-23 at 11 50 11 am](https://cloud.githubusercontent.com/assets/1118534/2781800/205f5e86-cb18-11e3-921a-fb2759006760.png)
![screen shot 2014-04-23 at 11 50 06 am](https://cloud.githubusercontent.com/assets/1118534/2781801/205f6142-cb18-11e3-84a8-2a04ac3f762f.png)
![screen shot 2014-04-23 at 11 49 58 am](https://cloud.githubusercontent.com/assets/1118534/2781802/205f801e-cb18-11e3-91e3-9a3734825113.png)