New icon for Turret Control Panels

![49zphs1](https://cloud.githubusercontent.com/assets/3828067/4128853/a03f937e-3313-11e4-81cb-d3516f925a5e.png)

It also now has a depowered state. (Not pictured)

I also organized the file a bit because it was all over the place.

So don't skewer me for code I didn't touch please.

I just changed update_icon(), and power_change(), and New()