Bug in get_3dfldr.F

[austinctodd]

There is a sign error in get_3dfldr.F where it checks if data that has a cycle_length needs to be read. Lines 149-154 say the following:

        IF (Liocycle) THEN
          Trec=MOD(Trec,Nrec)-1
          IF (Trec.le.0) Trec=Nrec-Trec
        ELSE
          Trec=Trec-1
        END IF

The issue is with Trec=Nrec-Trec , which makes Trec greater than nrec instead of cycling the integer. It should actually be Trec=Nrec+Trec to be consistent with get_2dfldr.F'