Draw the back accessory layer before the skin layer.

Here's how it looked before this change, with the Golden Wings overwriting two pixels on each arm and one pixel on each side of the face:
![backvsskin-old](https://cloud.githubusercontent.com/assets/3161425/2559596/6639d1ec-b782-11e3-8580-85fbcb0b0058.png)

And here's how it looks after this change:
![backvsskin-new](https://cloud.githubusercontent.com/assets/3161425/2559598/6df91a5a-b782-11e3-9b4a-ed18326deabe.png)