Corrected vertical integration in balance operator

[arango]

Ticket corrects the following:

• An update was made in ​src:ticket:373 to use the level of no motion when computing the balanced free-surface contribution in the balance operator. This strategy is only needed when integrating the non-hydrostatic relationship from the level of no motion (LNM_depth) to the surface.

This strategy is not needed when ZETA_ELLIPTIC is activated since an elliptical equation is solved (Fukumori et al., 1998; Weaver et al. 2005) to avoid the need for a level of no motion in the vertical integration. Therefore, ad_banlance.F, tl_balance.F, and zeta_balanced.F were changed to remove this integration option.

• Changed the Version variable to 3.4 in mod_ncparam.F:

           character (len=5  ) :: version = '3.4  '
  

• Allowed integer overflow in ran_state.F when using the gfortran compiler (Linux-gfortran.mk, CYGWIN-gfortran.mk, MINGW-gfortran.mk):

  $(SCRATCH_DIR)/ran_state.o: FFLAGS += -fno-strict-overflow
  

  Many thanks to Alexander Barth for ​reporting and solving this problem.