Minor modifs (not important)
Minor modif (looking for rho loss of precision)
Added Euler forward scheme for rho

Still fails the gradient test when rho!=0
Uniformised rho-schemes interface
Corrected the Leapfrog-Trapezoidal scheme

REF: Durran 1998 c.3.4.2
Still gradient test indicates loss of precision
when rho<>0.
I'm going to flush rho from kdvPseudoSpec
Passes the test if rho constant

If rho<0 (unstable), then there is a limit of
TLM validity not to be crossed as amplitude
rises.
Resolved an adjoint issue

Still issue with gradient test precision
debugging
Removed random seed (always the same values)

Better for debugging....
Also I separeted the two tests in Makefile
Testing one Leapfrog-Trapezoidal step

Fail slightly, suggesting the problem is there.
Only lowfreq rho and few nDt work...
Merging to master: explained the gradTest issue

It would seem that there is a maximum integration
time (resolution and parameter dependent) upon
which the gradient test will fail.  Increasing
the resolution seems to solve the issue.