+ SimDag:
+ * Kill the useless "rate" argument of SD_task_get_execution_time()
+ Everyone used to provide -1 as a value, it was not used, and the
+ semantic of a possible use wasn't even clear.
+ MSG:
+ * In trace replay, allow to have one trace file per process.
+ Give the specific trace file as argument of each process,
+ and call MSG_action_trace_run(NULL)
+ You can still have one merged file for each processes.
+