- renumberMesh now has -dry-run, -write-maps, -no-fields,
  -renumber-method, -renumber-coeffs options.

  * Use -dry-run with -write-maps to visualize the before/after
    effects of renumbering (creates a VTK file).

  * -no-fields to renumber the mesh only.
    This is useful and faster when the input fields are uniform
    and the -overwrite option is specified.

  * -renumber-method allows a quick means of specifying a different
    default renumber method (instead of Cuthill-McKee).

    The -renumber-coeffs option allows passing of dictionary content
    for the method.

    Examples,

       // Different ways to specify reverse Cuthill-McKee

       *  -renumber-method RCM
       *  -renumber-coeffs 'reverse true;'
       *  -renumber-method CuthillMcKee
       *  -renumber-coeffs 'reverse true;'
       *  -renumber-coeffs 'method CuthillMcKee; reverse true;'

       // Other (without dictionary coefficients)
       *  renumberMesh -renu...