Add namelist options for the cloud water / cloud ice tuning included from the KeyClim simulations

[oyvindseland]

Issue Type

Code Clean-up

Issue Description

The parameter values used in KeyClim simulations were only first guesses / tests and should be tuned. This is easier if they can be defined / specified in the namelist

Will this change answers?

No

Will you be implementing this yourself?

No

[DirkOlivie]

Does this need explicit namelist options? Cannot this just be the default?

[gold2718]

It might help if the parameters under discussion were listed here. I think the idea is to turn certain constants in the code into namelist options with the default value being the value from the KeyClim simulation code base. @oyvindseland , which constants do you see as good candidates for this treatment?