Additional CSS cleanup, changed btn-default to use white BG

1. Additional CSS cleanup.
2. Changed btn-default to use white BG so it shows up properly on pages where the background is #efefef. This now also matches the 'Import Contract' and 'Fixed Price' buttons at the top of the 'Add Contract' modal window.
![canceldefault](https://cloud.githubusercontent.com/assets/4713204/4973603/9d6039e6-68bb-11e4-911f-e408df47a66a.png)
![cancelhover](https://cloud.githubusercontent.com/assets/4713204/4973608/9fb9469c-68bb-11e4-991d-11c6bd1377f6.png)
![savebutton](https://cloud.githubusercontent.com/assets/4713204/4973667/109e008c-68bc-11e4-88e7-6f35b1f97c2f.png)


ping @Klakurka