Fix. Dropdowns are too narrow.

Dropdowns are a bit too narrow compared to other form fields. 

Example before:
![before](https://cloud.githubusercontent.com/assets/2812754/3131456/afcfcdfe-e804-11e3-9113-6c8cde70c587.png)

After:
![after](https://cloud.githubusercontent.com/assets/2812754/3131459/b88ba8dc-e804-11e3-9bca-2882af3a2357.png)