BUMP: Bump TubeTK to include SegmentTubes fixes
ENH: Use latest SegmentTubes fix to have the VesselExtractionStep work

Use the physical point parameter instead of the index parameter. Also add
a forgotten call to hide save results until the step is valid.
ENH: Automatically load the vessel file after VesselExtraction success

Since slicer doesn't support those files through the CLI architecture,
we can simply load it after the execution of segment tubes is succesfull.
Also factorize the getFilenameFromNode method in the WorkflowStep.
Merge branch 'fix-segment-tubes'

* fix-segment-tubes:
  ENH: Automatically load the vessel file after VesselExtraction success
  ENH: Use latest SegmentTubes fix to have the VesselExtractionStep work
  BUMP: Bump TubeTK to include SegmentTubes fixes