ENH: MergeAdjacentImages and others with registration to use TubeTK/Reg
BUG: Fixed use of simple averaging
ITK fft filter

Conflicts:

	Applications/ImageEditor/ImageEditor.cxx
	Applications/ImageEditor/QtImageEditor.cxx
	Applications/ImageEditor/QtImageEditor.h
Gaussian derivative implemented

Conflicts:

	Applications/ImageEditor/ImageEditor.cxx
	Applications/ImageEditor/QtImageEditor.cxx
	Applications/ImageEditor/QtImageEditor.h
Amend to merge commit
Move GaussianDerivativeImageSource to TubeTK/Base/Numerics
ImageViewer's bug fixed GaussianDerivativeImageSource uses template
FFTGaussianDerivativeIFFTFilter improvement
Add order vector in GUI
ENH: Add a physical coordinate for SegmentTubes

This is particulary useful when using this CLI in Slicer/VesselView since
that's what the markup give the module.
ENH: Make SegmentTubes executable only

In vesselview, we need the cli to write files to disk so they can be
reloaded after since slicer doesn't support natively .tre files.
FIX: Fix weird probe error when no seed is present
Merge pull request #283 from vovythevov/physical-coordinates-segment-tubes

Improve SegmentTubes
itktubeFFTGaussianDerivativeIFFTFilter available
BUG: Params from EvoOpt weren't set correctly for GradOpt
ENH: Improved registration and option for fast blending (experimental)
BUG: Missing path to Slicer coded downloaded during build.

Slicer/Libs/ITKFatoryRegistration is built and used by SEMCLI.  Path to
.h files were missing.
Merge pull request #284 from aylward/Merge

Merge
ENH: Bump ImageViewer to compile on MacOS
Merge pull request #285 from aylward/ImageViewerUpdate

ENH: Bump ImageViewer to compile on MacOS