ENH: Addition of the extension ModelToModelDistance

This extension contains one CLI module of the same name. It computes a point by point distance between two models loaded in Slicer or VTK volumes. It is based on vtkDistancePolyDataFilter. The distance can be signed or unsigned.

More information can be found on the documentation page of the extension:
http://www.slicer.org/slicerWiki/index.php/Documentation/Nightly/Extensions/ModelToModelDistance

Or on the NITRC page of the project:
https://www.nitrc.org/projects/meshmetric3d/

The source code is available on github:
https://github.com/NIRALUser/3DMetricTools
Update TCIA Browser: added missing path to resources(icons)
Merge pull request #612 from mehrtash/update-TCIABrowser

Update TCIA Browser:
Merge pull request #604 from fbudin69500/add-ModelToModelDistance

ENH: Addition of the extension ModelToModelDistance
ENH: ModelToModelDistance matches 3DMeshMetric format in vtk files when using VTK filter

-Scalar array is named "Distance" by the VTK filter "vtkDistancePolyDataFilter"
-Scalar array is renamed "Signed" if the computed is signed
-Scalar array is renamed "Absolute" if the computed distance is not signed
-An additional and constant field is added to the vtkPoyData and is called "Original"
Merge pull request #614 from fbudin69500/update-ModelToModelDistance

ENH: ModelToModelDistance matches 3DMeshMetric format in vtk files when ...