STYLE: code cleanup searchableSurface (issue #929)

- improve doxygen entries for searchable surfaces.

- support selection of searchable surfaces with shorter names.
  Eg,
      type   box | cylinder | ...;
  vs  type   searchableBox | searchableCylinder | ...;

tutorials/mesh/snappyHexMesh/addLayersToFaceZone/system/snappyHexMeshDict

@@ -23,7 +23,7 @@ addLayers       true;
 // Geometry. Definition of all surfaces. All surfaces are of class
 // searchableSurface.
 geometry
-{};
+{}
 
 
 

tutorials/mesh/snappyHexMesh/aerofoilNACA0012_directionalRefinement/system/snappyHexMeshDict

@@ -35,12 +35,11 @@ geometry
     }
     wake
     {
-        type searchableBox;
-        min (0.8 -0.1 -0.1);
-        max (2.0  0.1  0.1);
+        type box;
+        min  (0.8 -0.1 -0.1);
+        max  (2.0  0.1  0.1);
     }
-};
-
+}
 
 
 // Settings for the castellatedMesh generation.

tutorials/mesh/snappyHexMesh/flange/system/snappyHexMeshDict

@@ -38,12 +38,11 @@ geometry
     //- Refine a bit extra around the small centre hole
     refineHole
     {
-        type searchableSphere;
-        centre (0 0 -0.012);
-        radius 0.003;
+        type    sphere;
+        centre  (0 0 -0.012);
+        radius  0.003;
     }
-};
-
+}
 
 
 // Settings for the castellatedMesh generation.

tutorials/mesh/snappyHexMesh/gap_detection/system/snappyHexMeshDict

@@ -34,13 +34,11 @@ geometry
     }
     all
     {
-        type searchableBox;
-        min (-1000 -1000 -1000);
-        max (1000 1000 1000);
+        type box;
+        min  (-1000 -1000 -1000);
+        max  (1000 1000 1000);
     }
-
-};
-
+}
 
 
 // Settings for the castellatedMesh generation.