Add dropdown versions of blocks for artist toolbox

![image](https://cloud.githubusercontent.com/assets/206973/3803063/349de1ca-1c16-11e4-9382-b9e3bedb8371.png)

![image](https://cloud.githubusercontent.com/assets/206973/3803067/3c5a1366-1c16-11e4-811e-bd59cd61f3bf.png)

![image](https://cloud.githubusercontent.com/assets/206973/3803070/40dba79c-1c16-11e4-9012-479a51cfe6dc.png)