Material: Material appearance

Uses new material system for appearance

Each feature object now has a property called ShapeMaterial that
describes its physical properties. If it has a shape, it has a
material.

The ShapeColor attribute is replaced by a ShapeAppearance attribute.
This is a material list that describes all appearance properties, not
just diffuse color. As a list in can be used for all elements of a
shape, such as edges and faces.

A new widget is provided to allow the user to select materials in a
consistent fashion. It can also launch the material editor with its
more advanced capabilities.

src/App/GeoFeature.cpp

@@ -173,3 +173,12 @@ DocumentObject *GeoFeature::resolveElement(DocumentObject *obj, const char *subn
     return sobj;
 }
 
+App::Material GeoFeature::getMaterialAppearance() const
+{
+    return App::Material(App::Material::DEFAULT);
+}
+
+void GeoFeature::setMaterialAppearance(const App::Material& material)
+{
+    Q_UNUSED(material)
+}