COMP: Fix wrong CutMesh iterator type
COMP: Fix wrong CutMesh iterator type

Addresses:

  /home/matt/src/ITKExamples/src/Core/QuadEdgeMesh/CutMesh/Code.cxx:99:12:
  error: no member named '__1' in namespace 'std'
    for(std::__1::__tree_const_iterator<unsigned long,
    std::__1::__tree_node<unsigned long, void *> *, long>::value_type
    fIt : facesSet)
          ~~~~~^

Change-Id: I0bf7972e4df913be24fd01822c1327848ea7a14b

InsightSoftwareConsortium/ITKExamples,InsightSoftwareConsortium/ITKExamples,InsightSoftwareConsortium/ITKExamples,InsightSoftwareConsortium/ITKExamples,InsightSoftwareConsortium/ITKExamples