COMP: Fix shadowed declaration warning
COMP: Fix unused variable warning in BRAINSFitHelperTemplate

This commit fixes the following warning:

/path/to/BRAINSTools/BRAINSCommonLib/BRAINSFitHelperTemplate.hxx:1178:26: warning: unused variable ‘SplineOrder’ [-Wunused-variable]
       const unsigned int SplineOrder = 3;
                          ^
COMP: remove ITKV3_COMPATIBILITY entireley
ENH: Per requests of the slicer community, defaults changed.

Discussions with the Slicer registration community indicated that a
different set of defaults was requested.  These were created via
community input and the gui was re-organized to hide unnecessary values.