Mobile design cleanup

- consolidated login/registration to use the same css file and also a parent container class because they share the same styles
- fixed registration page & manage currencies page to be usable (still not great but better than before)

New:
![image](https://cloud.githubusercontent.com/assets/51415/4762224/41838cdc-5aff-11e4-8749-d77c84a4f3b9.png)
Old:
![image](https://cloud.githubusercontent.com/assets/51415/4762226/4d9a7c60-5aff-11e4-90f0-0523b9263613.png)

-----
Old:
![image](https://cloud.githubusercontent.com/assets/51415/4762246/8b107112-5aff-11e4-88ae-5649e9686266.png)

New:
![image](https://cloud.githubusercontent.com/assets/51415/4762255/ab22e304-5aff-11e4-9250-e21d135fbb7d.png)

Mobile:
![screen shot 2014-10-23 at 4 18 29 pm](https://cloud.githubusercontent.com/assets/3108007/4763041/f70e388a-5b0a-11e4-859a-81cb2be1a214.png)

Desktop:
![screen shot 2014-10-23 at 4 17 11 pm](https://cloud.githubusercontent.com/assets/3108007/4763035/de5e7840-5b0a-11e4-8f20-cfafb1dc56aa.png)