BUG: CurrentLevel was being set back to 0 on each level
BUG: CurrentLevel was being set back to 0 on each level

- Multiresolution framework calls PostProcessLevel after each level, not just at the very end.
- Can't find a function called only when the multiresolution is finished: so there will be a bug if the same registration filter object is used in a multiresolution framework to do multiple registrations.
- For now, the CLI will never do this so things work correctly

aylward/ITKTubeTK,KitwareMedical/ITKTubeTK,KitwareMedical/ITKTubeTK,matthieuheitz/TubeTK,thewtex/TubeTK,KitwareMedical/TubeTK,cdeepakroy/TubeTK,aylward/ITKTubeTK,LucasGandel/TubeTK,thewtex/TubeTK,KitwareMedical/ITKTubeTK,thewtex/TubeTK,aylward/ITKTubeTK,cdeepakroy/TubeTK,sumedhasingla/TubeTK,cdeepakroy/TubeTK,LucasGandel/TubeTK,KitwareMedical/TubeTK,aylward/ITKTubeTK,thewtex/TubeTK,LucasGandel/TubeTK,KitwareMedical/TubeTK,KitwareMedical/TubeTK,cdeepakroy/TubeTK,matthieuheitz/TubeTK,matthieuheitz/TubeTK,KitwareMedical/ITKTubeTK,sumedhasingla/TubeTK,LucasGandel/TubeTK,sumedhasingla/TubeTK,sumedhasingla/TubeTK,matthieuheitz/TubeTK