BUG: Use input RequestedRegion Index in SliceBySliceImageFilter internal.

Not all input images have [0,0,0] as their index.

Change-Id: I4c3bfade88be85f1aaf336b7ac62d5eb294d7091
ENH: LandmarkBasedTransformInitializer supports BSplineTransformType

Only the following transform types were supported by the
LandmarkBasedTransformInitializer class:
  VersorRigid3DTransform
  Rigid2DTransform
  AffineTransform

Now, support for the BSplineTransform is also added.
Also, I moved this class from the Modules/Core/Transform/ to the
Modules/Registration/Common/ to avoid module dependency cycle.

New implementations needed the ITKImageGrid be added to the
dependencies, and if this class was kept in ITKTransform, it would cause
a module dependency cycle.

Change-Id: I09b895627fcace1915ea8ade76f0f7f7273b5ffa
Merge topic 'SliceBySliceIndex'

000ed859 BUG: Use input RequestedRegion Index in SliceBySliceImageFilter internal.
Merge topic 'LmkTxInitializer_r'

559c7422 ENH: LandmarkBasedTransformInitializer supports BSplineTransformType