ENH: Use named inputs in BinaryReconstruction filters.

The named input ProcessObject functionality is put to use for the MarkerImage
and MaskImage in a backwards compatible way.

Change-Id: I7c252cc8afce3f627795aa1d8410328f61555610
STYLE: Remove redundant itk namespace.

Change-Id: I95194381f925477cb71119cc11e9a290bb5af124
Merge topic 'BinaryReconstructionThreadSafety'

7d1b1b2 STYLE: Remove redundant itk namespace.
285f3ac ENH: Use named inputs in BinaryReconstruction filters.