Merged in NRPJP-97-the-relation-between-processes- (pull request #13)

[NRPJP-97] Matching number of MPI processes with brain processes specified in experiment file

* [NRPJP-97] Matching number of MPI processes with brain processes specified in experiment file

* [NRPJP-97] Correcting the number of MPI processes in NestLauncher, not MPI Launcher

Approved-by: Kepa Cantero <cantero@fortiss.org>
Approved-by: Ugo Albanese <ugo.albanese@santannapisa.it>