Denomination

Make bitstamp app respect user's btc denomination

![before login](https://f.cloud.github.com/assets/412533/1972269/5cbf9668-8345-11e3-9605-99253a548a42.png)

![after login](https://f.cloud.github.com/assets/412533/1972270/6136854e-8345-11e3-82f0-680abbb36e48.png)