Icon for DevAssistant. Fixes #1271

Icon for DevAssistant. Issue #1271 

3 drafts:
![devassistant1](https://cloud.githubusercontent.com/assets/7050624/5420031/6e07bc46-8251-11e4-9d3f-61b5fdaf6cc6.png)
![devassistant2](https://cloud.githubusercontent.com/assets/7050624/5420033/6e09df1c-8251-11e4-95d1-3b710b8fe1d7.png)


![devassistant4](https://cloud.githubusercontent.com/assets/7050624/5420032/6e08a566-8251-11e4-8c43-eae7c6939c11.png)

The last one's pushed.