surfaceFeatures: Consistent plane specification for subsetting

Specifying a plane with which to subset feature edges is now done using
the same dictionary syntax used elsewhere in OpenFOAM. For example, in
system/surfaceFeaturesDict:

    subsetFeatures
    {
        // Include only edges that intersect the plane
        plane
        {
            planeType       pointAndNormal;
            point           (0 0 0);
            normal          (1 0 0);
        }

        ...
    }

tutorials/mesh/foamyQuadMesh/jaggedBoundary/system/surfaceFeaturesDict

@@ -24,10 +24,13 @@ includedAngle   175;
 
 subsetFeatures
 {
-    // Use a plane to select feature edges
-    // (normal)(point)
-    // Keep only edges that intersect the plane will be included
-    plane               (0 0 1)(-0.6 0.3 0.0);
+    // Keep only edges that intersect the plane
+    plane
+    {
+        planeType       pointAndNormal;
+        point           (-0.6 0.3 0);
+        normal          (0 0 1);
+    }
 
     // Keep nonManifold edges (edges with >2 connected faces where
     // the faces form more than two different normal planes)

tutorials/mesh/foamyQuadMesh/square/system/surfaceFeaturesDict

@@ -24,10 +24,13 @@ includedAngle   175;
 
 subsetFeatures
 {
-    // Use a plane to select feature edges
-    // (normal)(point)
-    // Keep only edges that intersect the plane will be included
-    plane               (0 0 1)(0 0 0);
+    // Keep only edges that intersect the plane
+    plane
+    {
+        planeType       pointAndNormal;
+        point           (0 0 0);
+        normal          (1 0 0);
+    }
 
     // Keep nonManifold edges (edges with >2 connected faces where
     // the faces form more than two different normal planes)