ENH: GeodesicActiveContourShapePrior deals with DerivativeSigma equal to zero

Similar to 6eb26b3, this commit manages the case that DerivativeSigma is
equal to zero for the GeodesicActiveContourShapePrior filter.

Change-Id: I1ee9ba910578c7ae41cb295ddcb5ee087c1b6e58
ENH: Add the ITK_INSTALL_LIBRARY_DIR to WrapITK.pth.

This allows the use of WrapITK in a virtualenv by symbolically linking to
WrapITK.pth in the site-packages directory.

Change-Id: Id27789be91fe5d48b7e3e3681fc56fb6b8c645ac
DOC: Make comment the Doxygen brief

The prior formatting was incorrect, and didn't not result in correctly
formatted output.

Change-Id: I59abb4948755669c9de76bd91e0a893610bc31f5
COMP: Test failure from numerical precision

A test was failing due to slight numerical precision differences
during computaiton on different machines.

Change-Id: I73371cdc25f8b6db774c7146036b25f0406d1c98
BUG: Memory leak introduced.

In git commit 5f1e8745fe68764273533693ae6624d4cafb1c42
a memory leak was introduced.

This patch clears that memory leak, and pushes the incorrect
constructor that had potentially dangerous use cases into
the ITK_FUTURE_DEPRECATED state.

Change-Id: I11a576389ee6fb9eb09793d2811d2291a7b72325
Merge topic 'gac-shapeprior-with-zero-derivativesigma'

a46334f9 ENH: GeodesicActiveContourShapePrior deals with DerivativeSigma equal to zero
Merge topic 'FixCannyEdgeDoxygen'

e6908a9b DOC: Make comment the Doxygen brief
Merge topic 'AddSmallNumericalToleranceForTest'

cdbd9ade COMP: Test failure from numerical precision
Merge topic 'wrapitk-pth-libraries'

7e645446 ENH: Add the ITK_INSTALL_LIBRARY_DIR to WrapITK.pth.
Merge topic 'ValgrindPatch'

2714a3b6 BUG: Memory leak introduced.