ENH: Use partial template specialization for iso value vis

Change-Id: Idf13cdf9ac1c2ccc136d3b2a306c8309930cb68c
PERF: Allow delete of NULL pointers

The deletion of a NULL value is a no-op in C++. Simplify code
by removing superfluous checks for NULL before deletions.

Part of issue: https://issues.itk.org/jira/browse/ITK-3182

Change-Id: I170fa7e143184fa5952e093e2884a3de7c527d71
ENH: Use file(COPY .. instead of exec_process.

exec_process is deprecated, and it is more efficient to avoid spawning a
process.

Change-Id: I72545d2acdd3f70f2814e49382593bc13f9e7d8f
BUG: {Opening,Closing}ByReconstructionImageFilter information propagation

The use of PreserveIntensities option in {Opening,Closing}ByReconstructionImageFilter
leads in tempImage creation, inputImage informations should have to be exported
to avoid exception in filtering process in case of non standard input image information.
informations are exported using CopyInformation method

Tests of OpeningByReconstructionImageFilter using
PreserveIntensities option and non zero origin and spacing image
(generated inside the test) have been added.

Change-Id: I7b47b305940a6d85e978b62012e8ca2dcc0d4323
COMP: Fix transform wrapping errors with ITK_WRAP_double OFF.

Change-Id: I01e12dc28dfba9c7a5959ca8f98051b26c8dac44
BUG: Fix memory leak error in itkHDF5TransformIO

There was a Valgrind error in itkIOTransformHDF5Test after the
TransformIO new API patch is merged.
The memory assigned to the double precision buffer was not freed after
it was used.
This error is addressed in this patch.

Change-Id: Idf6801cd8187cd244c2cdc36978dbdd570cae138
Merge topic 'valgrindMemoryLeak'

105887f BUG: Fix memory leak error in itkHDF5TransformIO
Merge topic 'Delete-Null'

a28028d PERF: Allow delete of NULL pointers
Merge topic 'WrapITKErrors'

e37610c ENH: Use file(COPY .. instead of exec_process.
Merge topic 'FixVisuLevelSet3D'

12b38cf ENH: Use partial template specialization for iso value vis
Merge topic 'FixPreserveIntensitiesOpeningByReconstructionImageFilter'

7519783 BUG: {Opening,Closing}ByReconstructionImageFilter information propagation
Merge topic 'WrapITKErrors'

b1a3bf9 COMP: Fix transform wrapping errors with ITK_WRAP_double OFF.
BUG: ConstPointer assigned to non-const raw pointer

itkImageToVectorImageFilter.hxx had a bug that the ConstPointer to the
input image was being assigned to a non-const raw pointer.  This
caused a compilation error.  This is fixed in this patch.

Change-Id: Ibeed0a37752caa60961be7071d99677cc4f87de9
Merge topic 'ImageToVectorBug'

5cd595e BUG: ConstPointer assigned to non-const raw pointer