Revert "Merge pull request #27 from alexeykudinkin/kuhn-munkres"

This reverts commit 92515499ec252d47a5d2a61121b91fd95f3bb5b8, reversing
changes made to 9681504586e103d7dc5a4670b6f76ddb37e3977b.
Merge pull request #45 from jgrapht/revert_try2

Revert "Merge pull request #27 from alexeykudinkin/kuhn-munkres"