Added allowFreeStandingZoneFaces flag

This determines when faceZones and cellZones are being meshed any zone faces
can only be on the boundary of the cellZone or also 'free standing'. The
latter option can be used to e.g. create free-standing baffles
(that do not separate two regions)

src/mesh/autoMesh/autoHexMesh/meshRefinement/meshRefinement.H

@@ -704,7 +704,11 @@ public:
             //- Put faces/cells into zones according to surface specification.
             //  Returns null if no zone surfaces present. Region containing
             //  the keepPoint will not be put into a cellZone.
-            autoPtr<mapPolyMesh> zonify(const point& keepPoint);
+            autoPtr<mapPolyMesh> zonify
+            (
+                const point& keepPoint,
+                const bool allowFreeStandingZoneFaces
+            );
 
 
         // Other topo changes