This updates the way in which FATES history output is flushed during
model initialization
utilizing a new FATES-side subroutine, flush_all_hvars.  This update
also makes corrections
to a subset of FATES testmods as well as expands the FATES test list by
duplicating two
existing tests to run on different compilers for better coverage.  The
FATES submodule tag
has been updated to the latest scientific tag as well.