fixed ugly outline around Switch fixes #299

Here is how it looks now. 

![image](https://cloud.githubusercontent.com/assets/2982512/5281307/1e9d36d8-7afc-11e4-9760-28267c4d6e2a.png)
![image](https://cloud.githubusercontent.com/assets/2982512/5281318/38698242-7afc-11e4-8f6e-116be64d4581.png)
![image](https://cloud.githubusercontent.com/assets/2982512/5281356/a4e3763a-7afc-11e4-8785-2518cb9271b6.png)

I have mentioned other widgets with malformed outlines in #299 but didn't change anything besides Switch.