Multiple-layered core shell particle

[johnaparker]

Implement a many-layered core-shell particle. Along with the core-shell particle, these particles are Mie-like and can be used inside miepy.sphere_cluster rather than going to the T-matrix approach. Additionally, the interior field calculations would need to be specialized.

[johnaparker]

W. Yang, "Improved recursive algorithm for light scattering by a multilayered sphere", Applied Optics 42(9), (2003)