Revision 97

Module pressure_var is now only used in gcm. Created local variables
pls and p3d in etat0, added argument p3d to regr_pr_o3.

In leapfrog, moved computation of p3d and exner function immediately
after integrd, for clarity (does not change the execution).

Removed unused arguments: ntra, tra1 and tra of cv3_compress; ntra,
tra and traent of cv3_mixing; ntra, ftra, ftra1 of cv3_uncompress;
ntra, tra, trap of cv3_unsat; ntra, tra, trap, traent, ftra of
cv3_yield; tra, tvp, pbase, bbase, dtvpdt1, dtvpdq1, dplcldt,
dplcldr, ntra of concvl; ndp1, ntra, tra1 of cv_driver

Removed argument d_tra and computation of d_tra in concvl. Removed
argument ftra1 and computation of ftra1 in cv_driver. ftra1 was just
set to 0 in cv_driver, associated to d_tra in concvl, and set again to
zero in concvl.