This is a somehow basic master/slaves example.

There is 3 kind of processes:
 * Master: creates some tasks, and dispatches them to its slaves
 * Forwarder: get tasks from master, and dispatch them further
 * Slave: get tasks from either master or forwarder, and run them
 
At the end of the execution:
 - the master sends FinalizeTask to every known slave to stop them
 - On reception of FT, forwarders send FT to every slave, and stop.
 - On reception of FinalizeTask, slaves stop.