modified on BitTorrent class 23-03-2014 11:01
update 23 march 2014 5.10 - note that each peer has their own cache/ neighbor
update 23 march 2014 20:18, explore differences among filestatus,rarestpieceset, and status variables
update march 24, 2014, 12.57 - explore the INTEREST message and getPiece(), next, customize this method to support the order of requested segment
update 26 maret 2014
update 1 april 2014