Update arguments to ImageRegistrationMethod4

Change-Id: I9f8c82ba7d771b18a8d81620757b3d7370fd6012
ENH: Add scales estimator option for regular step optimizer

Change-Id: Ief5543551e0c5bb5b0678c72bfefa112d60546b4
Merge topic 'SIMPLEITK-521_AddImageRegistrationMethodv4' into next

1995e2bd ENH: Add scales estimator option for regular step optimizer
94ae7dd7 Update arguments to ImageRegistrationMethod4