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)


![devassistant5](https://cloud.githubusercontent.com/assets/7050624/5420633/12172500-8258-11e4-8b9d-ec378a1e12a7.png)


The last one's pushed.