Adding testing input for ITK proper

Change-Id: I82b3caaaf1a8b647f1c542ca8dfc40c101e7af84
Adding wrapping for MergeLabelMapFilter

Change-Id: I086ac52d2cf225ca8a901030ee466228bfe4186e
Merge topic 'SIMPLEITK-512_AddLabelMapFilters' into next

171a550b Adding wrapping for MergeLabelMapFilter
b417184f Adding testing input for ITK proper