Planet shader

Here's all the channels from the planet material

1. _MainTex : the planet's albedo
2. _NormalMap : the normals
3. _PackedMap : ?
4. _EmissionTex : emissive texture (i.e. for lava planets), but it doesn't seem hooked up correctly in the shader
5. _NorthPoleDiffuse : specific texture for the north pole
6. _NorthPoleNormal : specific normals for the north pole
7. _SouthPoleDiffuse : specific texture for the south pole
8. _SouthPoleNormal : specific normals for the south pole