Add Attribute to FemMeshViewProvider python class to get all visible FemMesh faces.

src/Mod/Fem/Gui/ViewProviderFemMeshPyImp.cpp

@@ -66,6 +66,22 @@ void  ViewProviderFemMeshPy::setHighlightedNodes(Py::List arg)
 
 }
 
+Py::List ViewProviderFemMeshPy::getVisibleElementFaces(void) const
+{
+    const std::vector<unsigned long> & visElmFc = this->getViewProviderFemMeshPtr()->getVisibleElementFaces();
+    Py::List result( visElmFc.size() );
+
+    int i = 0;
+    for (std::vector<unsigned long>::const_iterator it = visElmFc.begin();it!=visElmFc.end();++it,i++){
+        Py::Tuple tup(2);
+
+        tup.setItem( 0,Py::Int((long)*it>>3) );
+        tup.setItem( 1,Py::Int((long)(*it&7)+1) );
+        result.setItem(i,tup);
+    }
+
+    return result;
+}
 
 
 PyObject *ViewProviderFemMeshPy::getCustomAttributes(const char* /*attr*/) const