Identity next

This updates developer.github.com with new identity assets.

![Screen Shot 2013-04-16 at 9 27 00 AM](https://f.cloud.github.com/assets/72919/386889/8019a5f6-a6b2-11e2-877f-ae8b53562cf2.png)
![Screen Shot 2013-04-16 at 9 27 04 AM](https://f.cloud.github.com/assets/72919/386891/8273f086-a6b2-11e2-9d35-8e119b2413da.png)