VTK OBJ importer duplicates vertices for each triangle

[mmcauliffe]

Importing the james.obj file from the built-in assets creates a mesh with 205,458 vertices (meshlab lists 34,913). The number of vertices is three times the number of faces (68,486). Exporting the mesh to a .stl file in meshlab and then importing it in Menpo results in the correct number of vertices. It looks like it's a bug in vtk.vtkOBJReader, since the number of verticies reported at https://github.com/menpo/menpo3d/blob/master/menpo3d/io/input/mesh/base.py#L200 is the erroneously high number.