ENH: use faceTraits for managing differences between face representations

src/surfMesh/MeshedSurface/MeshedSurface.C

src/surfMesh/MeshedSurface/MeshedSurface.H

src/surfMesh/MeshedSurface/MeshedSurfaceCore.C

src/surfMesh/MeshedSurface/MeshedSurfaceI.H

src/surfMesh/MeshedSurface/MeshedSurfaceIO.C

src/surfMesh/MeshedSurface/MeshedSurfaceNew.C

src/surfMesh/MeshedSurfaceProxy/MeshedSurfaceProxy.C

src/surfMesh/MeshedSurfaceProxy/MeshedSurfaceProxy.H

src/surfMesh/UnsortedMeshedSurface/UnsortedMeshedSurface.C

...surfMesh/UnsortedMeshedSurface/UnsortedMeshedSurfaceNew.C

src/surfMesh/surfaceFormats/ac3d/AC3DsurfaceFormat.C

src/surfMesh/surfaceFormats/gts/GTSsurfaceFormat.C

src/surfMesh/surfaceFormats/nas/NASsurfaceFormat.C

src/surfMesh/surfaceFormats/obj/OBJsurfaceFormat.C

src/surfMesh/surfaceFormats/off/OFFsurfaceFormat.C

src/surfMesh/surfaceFormats/starcd/STARCDsurfaceFormat.C

src/surfMesh/surfaceFormats/stl/STLsurfaceFormat.C

src/surfMesh/surfaceFormats/tri/TRIsurfaceFormat.C

src/surfMesh/surfaceFormats/vtk/VTKsurfaceFormat.C