[Mitgcm-support] close to c37

[mitgcm-support at dev.mitgcm.org]

Hello,

I have check-in the last few changes That I mentioned yesterday
about non-hydrostatic pickup.
And following the MITgcm CVS policy: "no code should be left in limbo 
for extended period", I propose to tag the present version "checkpoint37".

Here after I summarize the changes since ckp36 (--> for tag-index).

Jean-Michel
----
o mdsio.F routine split and packaged in pkg/mdsio
  (mdsio.F and mdsio_gl.F still exist in eesupp/src but are not
   used unless genmake -disable=mdsio)                                                 
o allow a more precise surface-geopotential gradient for the atmosphere 
  taking into account the change in space of Alpha (=1/rho) at the surface.
o variable "etaN" (replace cg2d_x) is the surface R-anomaly [r unit]
  (ocean: sea surface height [m] / atmos: surface pressure anomaly [Pa])
o Change in units: Phi_Hydrostatic (=phiHyd), Phi_Surface(=cg2d_x) and 
  Phi_NonHydrostatic (=cg3d_x), all have now the dimension of a potential 
  [m2/s2] (pressure/rhoConst in the ocean ; Geo-Potential in the atmosphere).
o Time-Average diagnostics defined as a pseudo package "timeave".
o pickup files : old pickup (before c35) did not work with new code (c35 
  and after) unless activating 2 commented lines in initialise-varia.
o Non-Hydrostatic pickup file Pb fixed. 
o bug with Rigid-lid version (since c35) fixed.