Feature/extra code

meshes/square-quads.geo

+Point(1) = {0,0,0,0.1};
+l[] = Extrude {1,0,0} {
+      Point{1}; Layers{4};
+};
+s[] = Extrude {0,1,0} {
+      Line{l[1]}; Layers{4}; Recombine;
+};
+Physical Surface(0) = {5};
+Physical Line(1) = {1};
+Physical Line(2) = {4};
+Physical Line(3) = {2};
+Physical Line(4) = {3};