extension for Munkres' solution to Assignment problem

 The Algorithm::Munkres module extends the solution of Assignment problem
 for square matrices to rectangular matrices by padding zeros. Thus a
 rectangular matrix is converted to square matrix by padding necessary zeros.
 .
 Assignment Problem: Given N jobs, N workers and the time taken by
 each worker to complete a job then how should the assignment of a
 Worker to a Job be done, so as to minimize the time taken.