These failures are already tracked with derecho versions

This will be reverted once issue ESCOMP#2423 has been addressed

This also adds a corresponding namelist build unit test and similar
test to check that sp mode + spitfire fails

Merge b4b-dev

Merge b4b-dev

Some fixes for run_neon that came up in ctsm5.1.dev172.
Small bug fix for units of vector format hillslope hydrology.
Start adding PLUMBER2 users-mods (NOT functional)

FATES API35 parameter file update

FATES default allometry parameter file update

This updates the default FATES parameter file which includes a number
of changes:

   - Default global tree pft allometry update
   - New allometric mode options
   - New scaling coefficients for alternative leaf maintenance respiration
   - New switch to control the use of host land model day length scaling factor

This also incorporates some testing additions and clean up, including:

   - Removes cheyenne expected failure tests that have been converted to derecho
   - Adds a 5x5_amazon test to aux_clm and the expected failures list
   - Temporarilry converts a fates 5x5_amazon test to f10 test
   - Adds namelist check and corresponding unit test to make sure fates hydro
     and fates satellite phenology mode can not be used together

The FATES externals tag is also updated which includes a number of bug fixes
and the addition of new history output.

Merge b4b-dev branch into master.