Use std::unordered_map & std::unordered_set.
Use std::unordered_map & std::unordered_set instead of vtksys::hash_map and vtksys::hash_set. Since we now use C++11, we can use these new standard library containers.
Use std::unordered_map & std::unordered_set instead of vtksys::hash_map and vtksys::hash_set. Since we now use C++11, we can use these new standard library containers.