fvsetup: define $ARCHIVE in fstats_run job script

[gmao-jstassi]

If the forecast statistics need to be rerun after a job has completed and the experiment is using a non-default $ARCHIVE location, then the fstats_run job script will not be successful unless ARCHIVE is set properly in the window environment that runs the job. To avoid this problem, fvsetup will be modified to define the ARCHIVE variable within the fstats_run script.

[gmao-jstassi]

An unrelated update needed in fvsetup is a needed syntax correction, as pointed out by Meta S.

         cat \$PBS_NODEFILE | tail +2 > \$FVWORK/GCM_list

needs to be changed to

         cat \$PBS_NODEFILE | tail -n +2 > \$FVWORK/GCM_list