+ - added a regression test about this in datadesc_usage
+ * Allow the exchange of 0-long dynamic vectors.
+ - for that, use -1 as indicator of dynamic size instead of 0
+ - This implied to change any size from unsigned long to long,
+ reducing a bit communication abilities, but I guess that with
+ 64bits being quite common, this is more than enough.
+ - This also induce a protocol change, thus bumping network protocol
+ version from 0 to 1 (if we have external users, we have to get
+ clean on that point too ;)
+ - added two regression tests about this in datadesc_usage
+ * Be more verbose when propagating local exceptions
+ This helps debugging.
+ * Display the status of simulated processes when receiving SIGINT in
+ simulation mode
+