BUG: Fix ITK Path test failures

This patch corrects a bug in 706a6bf6e04534c7ea8b98fd9cfbd0dc03b4a596.
Also http://review.source.kitware.com/#/c/9693/

Previously the IncrementInput function in itkPolyLineParametricPath
was not returning the correct offset.

This also deletes the accidental push of the
ExtractOrthogonalSwath2DImageFilterTest.png to the main repository
as well as move the location of the MD5 sum file to migrate away
from Testing/Data.

Change-Id: Id66f375de3ddfc031364b12d7fa795682f8f494b
Merge topic 'itkPathTestFailures_32bits'

dc42b3f BUG: Fix ITK Path test failures