Changes

In the previous commits for the --background-rcm option of pyplotgen,
I had previously thought that the code to extract values of rcm from
a file wanted the case name as input, but in actuality it required
the directory name instead of the case name. I am correcting that
error in this commitment.

I am updating the --background-rcm option of pyplotgen to make two
changes:

1) Use a grayscale color map.
2) Set the maximum of the colorbar to be twice the largest value in
the rcm plot so that the colors aren't so dark.

BIT_CHANGING for lscale setup. Updated configurable_model_flags.in and model_flags.F90 - CLUBB ticket #1102 (#1108)

- Added new flags to inut/tunable_parameters_Lscale/configurable_model_flags.in
- Changed default setting for l_use_tke_in_wp3_pr_turb_term in model_flags.F90 from false to true