Glazing featureType bad inheritance
Created by: oliviertournaire
From Romain Nouvel: "The featureType Glazing (which may have several glazes and gas gapes) is actually not a "Material" but a 'LayerComponent'. Then, it should not inherit from 'AbstractMaterial' but from 'LayerComponent'. Following that, the 'OpaqueMaterial' object should be renamed as 'SolidMaterial' (with the same parameters, at less for the first release)."