Bring in current code changes being used by Cecile

[cacraigucar]

Issue Type

Other (please describe below)

Issue Description

Need to bring in code changes and namelist settings that @cecilehannay is using for her testing configuration

Part of this work requires new CLUBB externals (https://github.com/ESCOMP/CAM/issues/956) and clubb_intr.F90 first. Example can be seen in the SourceMods in one of @cecilehannay tau's runs:

/glade/p/cesmdata/cseg/runs/cesm2_0/b.e23_alpha16g.BLT1850.ne30_t232.076

Plus all the user_nl_cam settings for clubb tau's. @Katetc

Will this change answers?

Yes

Will you be implementing this yourself?

Yes