added BL exemaples

benchmarks/boundaryLayers/lann_ver1.geo

+Mesh.CharacteristicLengthExtendFromBoundary = 1;
+Merge "lann_ver1.stp";
+
+MeshAlgorithm Surface {5,6}  1;
+
+/// Create a boundary layer field
+Field[1] = BoundaryLayer;
+/// Edges in the symmetry plane from which BL meshes are extruded
+Field[1].EdgesList = {3, 4};
+/// Faces in the volume from which BL meshes are extruded
+Field[1].FacesList = {3, 4, 5, 6};
+//// Mesh Size far from the surface
+Field[1].hfar = 1000;
+/// Normal size to the wall
+Field[1].hwall_n = .12;
+/// Tangent size on the wall
+Field[1].hwall_t = 10;
+/// Growth rate of the BL 
+Field[1].ratio = 1.4;
+/// Maximal Thickness of the BL
+Field[1].thickness = 8.12;
+/// Edges in the volume where fans of elements are created 
+/// This should be either closed or end in the symmetry plane 
+Field[1].FansList = {6,7,8,11,10,12};
+/// Vertices in the symmetry plane where fans of elements are created 
+Field[1].FanNodesList = {3, 4};
+/// Set the boundary layer field to be field 1
+BoundaryLayer Field = 1;
+
+Characteristic Length {5, 6, 7, 3, 4} = 10;
+Surface Loop(129) = {1,2,3,4,5,6};
+Volume(1000) = {129};
+