ENH: Make IntialMoving and InitialFixed transforms decorated inputs

This enhances the ability to change multiple registrations together.

Change-Id: Id88f479df3c13e4193d8d5ce049f6651d1400c3f
ENH: Update SimpleRegistration test

This is using the latest best practices for the ImageRegistrationMethodv4.

1) InPlace input, instead of modifying output.
2) Using GetTransform, to get the output object of the filter
3) Connecting multiple registrations together with a pipeline
4) Correcting the call back to print at each initialization of a level

Change-Id: I92f208e55adf795de110f90a591c616621b14d81
BUG: Don't create new Decorator in GenerateData

Use the Decorator already created and set the output transform to be
held by the existing container. This allows the output DataObject to
be connected to the next filter, and reused. If the output DataObject
is changed then pipeline connection is broken.
BUG: Use referenceImage for output information

Actually use the reference image to set the output information of the
displacement field. Also use named input macros for inputs.

Change-Id: Id4caec8285544d1e7fec335bdf448191f4881da8
Merge topic 'UseNamedInputForTransformToDisplacementField'

6212020b BUG: Use referenceImage for output information
Merge topic 'ImageRegistrationMethodv4PipelineInputs'

ff88bf33 BUG: Don't create new Decorator in GenerateData
99fc98f8 ENH: Update SimpleRegistration test
965331d0 ENH: Make IntialMoving and InitialFixed transforms decorated inputs
STYLE: Remove unnecessary comments.

Change-Id: I70c5152252264b68ed9d5a8dbaa0675a6d20a73f
Merge topic 'ImageRegistrationMethodv4PipelineInputsRmCmt'

7634bc82 STYLE: Remove unnecessary comments.
ENH: Adding some ImageIO libraries as shared

By making these libraries shared they will only be registered once
into the ImageIOFactory.

Change-Id: Ie11f9ea9975bb42463894201ae308e0dcbaee95b
BUG: Expose unusable functions

These functions were not covered in code coverage, and they
do not build.

Change-Id: Ie30712bc89ae0af79c05125178e363ad98bd5325
BUG: Incomplete refactoring of member variable name

The member variable name for this class is m_Offset.  These were
incorrectly coded, but went undiscovered due to lack of coverage,
and the fact that these functions are never used.

Change-Id: I7464d2b06d827288d44734c8b6af894d55ba69a5
STYLE: Allow system installed expat library with ITK_USE_SYSTEM_EXPAT=ON

Change-Id: I848f006063f27de4cdaf35e3a84de102caadb39f
BUG: Fix memory leak in LBFGSBOptimzierv4

Valgrind defect detected for the LBFGSBOptimizerv4:
http://open.cdash.org/viewDynamicAnalysis.php?buildid=3356652

Change-Id: I2cf4515d436c085c59a3f9ab54ca9a5f7e4a5f89
ENH: Uninitialized scalar field

Coverity defect:
Non-static class member is not initialized in this constructor nor in
any functions that it calls.

These were missed or new since the previous patch addressing this defect.

Change-Id: I369c7ed5ca9bece63ad30f4be4d9f00e1dd13fbd
Merge topic 'FixIncorrectMemberVariableNameAccess'

89e2a618 BUG: Incomplete refactoring of member variable name
5984b22d BUG: Expose unusable functions
ENH: Add distance vector to KdTree search API

In KddTree class, the distance vector is computed by the internal
"NearestNeighbors" class. However, this distance vector is not provided
as an API, instead in the examples the "EuclideanDistanceMetric" is used
to compute the distance vector.
This patch adds a new signature for the KdTree::Search function that
returns the distance vector as an argument.
Also a test unit is designed that shows that distances computed by the
metric are the same as the distances taken directly from the search
function.

Change-Id: I8130d73c1306caff2327b2ecd764dc84f2e95d12
Merge topic 'Coverity_UninitializedScalarField2'

51843eae ENH: Uninitialized scalar field
Merge topic 'lbfgsb_ml2'

3dd89bae BUG: Fix memory leak in LBFGSBOptimzierv4
Merge topic 'addDistanceVectorToKdTree_2'

45276d5c ENH: Add distance vector to KdTree search API
Merge topic 'ExternalExapt_ITK_USE_EXTERNAL_EXPAT'

ad260804 STYLE: Allow system installed expat library with ITK_USE_SYSTEM_EXPAT=ON