[WIP] MSM contract editor

![image](https://cloud.githubusercontent.com/assets/206973/4947067/942757ba-661d-11e4-915d-4f14cf71ea90.png)

![image](https://cloud.githubusercontent.com/assets/206973/4947068/973fb9d8-661d-11e4-936c-cdc06f82b3ab.png)