ENH: new sampling type "surfaceCut"

- an alternative to distanceSurface (with distance zero) that uses
  a cell cutting approach instead of an iso-surface.

tutorials/compressible/rhoSimpleFoam/squareBend/constant/triSurface/angledPlane1.obj

@@ -0,0 +1,25 @@
+# An angled plane with (1,1,1) normal
+o angledPlane1
+
+# Full extent
+# v -0.15 -0.025  0.025
+# v -0.10 -0.025 -0.025
+# v -0.05 -0.075 -0.025
+# v -0.10 -0.075  0.025
+
+# Embedded, ending at cell
+# v -0.135 -0.0325  0.0175
+# v -0.100 -0.0325 -0.0175
+# v -0.065 -0.0675 -0.0175
+# v -0.100 -0.0675  0.0175
+
+# Embedded, ending mid-cell
+
+v -0.1425 -0.02875  0.02125
+v -0.100  -0.02875 -0.02125
+v -0.0575 -0.07125 -0.02125
+v -0.100  -0.07125  0.02125
+
+f 1 2 4
+f 2 3 4
+# EOF

tutorials/compressible/rhoSimpleFoam/squareBend/system/samplingDebug

@@ -62,6 +62,32 @@ debug
             surfaceName angledPlane.obj;
         }
 
+        angledPlaneCut
+        {
+            type        surfaceCut;
+            triangulate false;
+            surfaceType triSurfaceMesh;
+            surfaceName angledPlane.obj;
+        }
+
+        angledPlane1
+        {
+            type        distanceSurface;
+            distance    0;
+            signed      true;
+            regularise  true;
+            surfaceType triSurfaceMesh;
+            surfaceName angledPlane1.obj;
+        }
+
+        angledPlane1Cut
+        {
+            type        surfaceCut;
+            triangulate false;
+            surfaceType triSurfaceMesh;
+            surfaceName angledPlane1.obj;
+        }
+
         disk1
         {
             ${_disk1}