Add network multicast to FBAE

[simatic]

Total order broadcast algorithms like Ring Paxos or FastCast use nework multicast to guarantee their performances ==>

• Add network multicast (on local network) to FBAE
• Add a program argument (-m ?) to specify that the tested algorithm may use network multicast instead of multicast based on n unicasts.
• Modify Sequencer algorithm so that it can also use network multicast when this new program argument is set.