Enhance edgeMesh to support more formats.

Read only support:

  .bdf, .nas - NASTRAN format. Handles both CBEAM and CROD as lines.
  CROD is what Hypermesh happens to output.

Write only support:

  .vtk - VTK legacy format in ASCII

Read/write support:
  .eMesh - native format, which is simply a list of points, edges
      with an additional IOobject header that lets them be moved about
      easily to use as a featureEdgeMesh.

  .inp - STAR-CD inp/cel/vrt combination
       IOobject header)

  .obj - Alias waverfront format

Radically simplify surfaceFeatureConvert by using the new edgeMesh
functionality.