[vtkusers] Create an actual mesh from a set of "connected" triangles

[Bryn Lloyd]

Hi David,

Your dolphin mesh contains two triangles that share all three vertices  
(at the end of the top fin).
If you select these two triangles in paraview, invert the selection,  
and extract it, then finally call the fill holes filter, the mesh  
seems to be OK.

I tested the result for following things:

Compatibility test: Passed
Point coincidence test: Passed
Duplicate tris test: Passed
Additionally, meshing it using tetgen and extracting the surface  
returns the identical surface.

Here you can get it/test it.
http://www.vision.ee.ethz.ch/blloyd/dolphin_fixed.vtk

bye
Bryn