Adapter for type std::vector <std::vector <double> > was implemented.
Error access out of bounds for nonsquare matrices was fixed (error was found using valgrind in test MunkresTest.solve_3x2_NonObviousSolutionCase001_Success).
Minor improvements of performance of step1. Changes were made based on the next points: first: at the begin of stage1 mask_matrix always is empty; second: after putting STAR into current row the algorithm interrupts loop (so it is not necessary to check STARs into current row); third: matrix is iterated by the algorithm from up to down (so it is not necessary to check STARs in bottom rows).
Updating to the last upstream changes (merge branch 'master' of https://github.com/saebyn/munkres-cpp).