Move SNICAR parameter to parameter file

[wwieder]

In this thread, @cenlinhe recommended moving the following parameters to the CLM parameter file.
(1) C2_liq_Brun89 (wet aging coeff, on parameter file),
(2) snw_rds_refrz (refrozne grain size, on parameter file),
(3) fresh_snw_rds_max (max fresh snow grain size) AerosolMod.F90,
(4) snw_rds_min (cold snow size), AerosolMod.F90
(5) scvng_fct_mlt_bcphi, scvng_fct_mlt_bcpho, scvng_fct_mlt_dst1~4 src/biogeophys/SnowHydrologyMod.F90

This isn't urgent, but could be helpful for subsequent OAAT parameter perturbation experiments as we look at tuning snow albedos.

[slevis-lmwg]

Linking (as related) another list of snow params being discussed that already appears in the params file.

These are the params that I need to add to the params file to complete this issue:
(3) fresh_snw_rds_max (max fresh snow grain size) AerosolMod.F90,
(4) snw_rds_min (cold snow size), AerosolMod.F90
(5) scvng_fct_mlt_bcphi, scvng_fct_mlt_bcpho, scvng_fct_mlt_dst1~4 src/biogeophys/SnowHydrologyMod.F90

[slevis-lmwg]

This parameter (fresh_snw_rds_max) moved from the namelist to the params file. I have a feeling this means that I need to update the clm50 and clm45 params files, as well.

Now that I think about it, I need to add all these params to the clm50 and clm45 params files.