an MPI error occurs when testing the "heatTransfer write" example using MPI aggregate method

Created by: lwan86

This is the MPI error: "*** The MPI_Comm_free() function was called after MPI_FINALIZE was invoked. *** This is disallowed by the MPI standard."

It seems that "MPI_Comm_free(&m_Comm)" function is called in the destructor of "MPIAggregator" class, which is called after the "MPI_Finalize()" at the end of the main function of the "heatTransfer write" example.