Add a new Infiniband network model, based on the works of Jerome Vienne.

This computes penalties on communications to account for the slowdowns experimented on real systems, and modeled by jerome
check http://mescal.imag.fr/membres/jean-marc.vincent/index.html/PhD/Vienne.pdf for details

known issue: doesn't work yet with permanent receive mode, as some surf actions are not released properly