This switch allows to compute Coriolis terms, both horizontal (in 2.Omega.sin(Phi))
and NH (in 2.Omega.cos(Phi)), using the averaged transport (with face edge length
and hFac factor), as done previously in V.I. for horizontal Coriolis.

For deep-model, absorb the NH-metric terms w.(u,v)/r into vertical advection
by advecting the product "deepFac x (u,v)" (instead of just u,v).

- Add recip_hFacW/S (previously commented out) in new expression
  (selectCoriScheme=4) of NH coriolis f'*W term
- remove hFacW/S from gW-Cori in selectCoriScheme=4 code and keep previous
  selectCoriScheme=4 code (with hFacW/S) under selectCoriScheme=6 block

- New Spherical-Metric term form using grid-spacing finite differences (instead
  of analytical tan(Phi)/rSphere), supposed to improve both AM and KE conservation.
  Used (turned on) when selectVortScheme=1,2.
- Add option to absorb the spherical-metric terms uMetricTerms = u.v.tanPhi/r
  into meridional advection by advecting the product "dxC x u" (instead of just u).
  Used (turned on) when selectVortScheme=2.
Note: for now, re-cycle Flux-Form unused param "selectVortScheme" for this.

This option (selectCoriScheme=6, in mom_w_coriolis_nh.F) was left from early
test, with hFacW/S multiplying uVel,vVel, but without scaling by any recip_hFac.
The changes here fix this issue as the gW-Cori term is now divided by the
grid-cell thickness at the wVel location (new argument recip_rThickC).

Two improvements:
- single CPP option "MOM_USE_OLD_DEEP_VERT_ADV" in MOM_COMMON_OPTIONS.h to
  disable changes to vertical advection for deepAtmosphere=T
- fix for the case useNHTerms=F with deepAtmosphere=T.
Done by keeping a local copy of deepFacC in MOM_VISC.h, and adding 1 new
argument to S/R mom_u_adv_wu.F, mom_v_adv_wv.F, mom_vi_{u,v}_vertshear.F

This new option (with selectCortScheme=4) skip the division of vorticity
by hFacZ and replace it with tendency scaling by recip_hFacW/S
Also:
 - remove code related to "upwindVort3" (was hard-coded to FALSE)
 - add some missing "_d 0" ; + minor indentation changes

no need to hack selectCoriScheme params and leave mom_vi_coriolis.F unchanged

- no need to hack selectVortScheme param
- compute advection tendency in separated block if selectMetricTerms
  This makes sure results will not be affected (at trucation level)
  with current default metric-terms.
- minor cleaning in mom_u/v_coriolis.F and mom_u/v_adv_wu/v.F

also rename 2 local variables (vF & v4F) more inline with other S/R
and improve description