saveModel needs to handle multiple model types

[famulare]

Right now, saveModel can only output a single csv. This works for smoothingModels, but probably will not work for latentField models in which there are both smoothing outputs and latentField outputs. I'm going to try to keep everything in one file as it makes provenance easier to track and retrieval for later manipulation in REACT easier, but I'm not sure that's possible.

[famulare]

This is addressed in c9e6157, but all this will go away when @devclinton refactors modelServR