MPI_LB and MPI_UB deprecation warnings

MPI_LB and MPI_UB macros are deprecated in MPI-2 and should replaced by the function MPI_Type_get_extent

See here for more info: https://www.open-mpi.org/doc/v1.8/man3/MPI_Type_get_extent.3.php

mentioned in issue #17 (closed)

mentioned in merge request !84 (merged)

@marco.agnese You can test !84 (merged) if you want. It should fix this issue.

Status changed to closed by commit 154cfac7

Status changed to closed by merge request !84 (merged)

mentioned in commit 154cfac7

Mentioned in commit 154cfac7