+ * New: int MSG_task_probe_from_host(int channel, m_host_t host): returns
+ the number of tasks waiting to be received on channel and sent
+ by host. [AL]
+ * New: MSG_error_t MSG_task_get_from_host(m_task_t * task, int channel, m_host_t host);
+ waits for the first task coming from a given host.. [AL]
+