Revision 215

size(snow) is now knon in interfsurf_hq.

Renamed snow to fsnow in clmain, same name as corresponding actual
argument. We can then rename ysnow to simply snow in clmain, same name
as corresponding dummy argument of clqh. No need to initialize local
snow to 0 since it is only used with indices 1:knon and already
initialized from fsnow for each type of surface. If there is no point
for a given type of surface, fsnow should be reset to 0 for this
type. We need to give a valid value to fsnow in this case even if it
will be multiplied by pctsrf = 0 in physiq.

In physiq, no need for intermediate zxsnow for output.

Removed unused arguments tsurf, p1lay, beta, coef1lay, ps, t1lay,
q1lay, u1lay, v1lay, petAcoef, peqAcoef, petBcoef, peqBcoef of
fonte_neige, with unused computations of zx_qs and zcor. (Same was
done in LMDZ.)