Simplification of soil texture processing, cf ticket #416: when using the Zobler map, the soil parameters are no more taken from 3-value "FAO" vectors in constantes_soil_var.f90, but from 13-value USDA vectors, owing to a pointer fao2usda. A 5-day running test with the Zobler map shows no changes, but over Greenland (class 6=ice in Zobler map).