ENH: new PDRblockMesh mesh generation utility (issue #1216)

- While a rectilinear mesh can be created with blockMesh, not every mesh
  created with blockMesh will satisfy the requirements for being a
  rectilinear mesh.

  This alternative to blockMesh uses a single block that is aligned
  with the xy-z directions and specifications of the control points,
  mesh divisions and expansion ratios. For example,

    x
    {
        points  ( -13.28 -0.10 6.0 19.19 );
        nCells  (  10  12 10 );
        ratios  ( 0.2   1  5 );
    }

    y { ... }
    z { ... }

  With only one block, the boundary patch definition is simple and the
  canonical face number is used directly. For example,

    inlet
    {
        type    patch;
        faces   ( 0 );
    }
    outlet
    {
        type    patch;
        faces   ( 1 );
    }

    sides
    {
        type    patch;
        faces   ( 2 3 );
    }

    ...

- After a mesh is defined, it is trivial to retrieve mesh-related
  information such as cell-volume, cell-centres for any i-j-k location
  without an actual polyMesh.

STYLE: remove -noFunctionObjects from blockMesh

- no time loop, so function objects cannot be triggered anyhow.

tutorials/mesh/PDRblockMesh/box0/system/fvSolution

@@ -0,0 +1,18 @@
+/*--------------------------------*- C++ -*----------------------------------*\
+| =========                 |                                                 |
+| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
+|  \\    /   O peration     | Version:  v1812                                 |
+|   \\  /    A nd           | Web:      www.OpenFOAM.com                      |
+|    \\/     M anipulation  |                                                 |
+\*---------------------------------------------------------------------------*/
+FoamFile
+{
+    version     2.0;
+    format      ascii;
+    class       dictionary;
+    location    "system";
+    object      fvSolution;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+// ************************************************************************* //