Icons for Stuntrally + Editor, fixes #1031

Icon for **Stunt Rally**, Issue #1031 
![stuntrally](https://cloud.githubusercontent.com/assets/7050624/5086560/462bb9d4-6f1e-11e4-92d7-8b66291e3525.png)

Icon for **Stunt Rally Track Editor**
![sr-editor](https://cloud.githubusercontent.com/assets/7050624/5086565/57aea6ee-6f1e-11e4-9129-6c3b4139e2c2.png)

Alternative Icons:
![stuntrally2](https://cloud.githubusercontent.com/assets/7050624/5086570/619d6320-6f1e-11e4-8c16-f8855e5913ad.png)
![sr-editor2](https://cloud.githubusercontent.com/assets/7050624/5086572/671b6144-6f1e-11e4-9c47-9c4408fbcf4d.png)