-it is made now in the increasing or decreasing kx order
-the order is decided with the sign of the jump (= sign of the ExBrate)

also improved the way to init from image

-kx is now 2D (ky dependant)
-kperp^2 array for computation reduction
-routines to update the grids

The perpendicular pressure effects are already added above
so this commented part is useles

avoid incoherent value in terminal

 in restart now

to avoid /0 when P=0

+ explanation of the structure

for adaptive time stepping
and cleaning