1.43 - minor updates and features

- resample parallelizes on Windows now
- resample uses rng_seed correctly now
- resample recomputes WAIC now
- added dcategorical and softmax for multinomial regressions
- fixed a rare issue with map when parameters where in a list
- added first draft geometric and categorical templates to map2stan
- precis shows Rhat as well as n_eff now, for map2stan fits
- fixed a bug with sim, so it recognizes all linear models in map fits.
Also fixes a bug with postcheck, with relies on sim.