ENH: Updating to ITK v4.4.1 release tag

Change-Id: Id567c91c19321c86a43f604a55d6e7d86f1a315a
Merge topic 'SIMPLEITK-400_UpgradeTowardsITK_4.4.1' into next

dc39f53 ENH: Updating to ITK v4.4.1 release tag