Renamed Torrent class to Tracker class.  Stage 1 of decoupling things from the Torrent class.
Fixing tests to deal with the decoupling of peers and tracker.
Fixed the peer creation problem that was making handshakes fail.  A peer must be created with a valid hashed info.  An assert has been added to require this, so I don't have to deal with this problem again.
Added an optional peer id to the Tracker constructor.
Updated Swarm constructor to provide a peer id to the Tracker.
First iteration of the block directory.  So far it is just an array of booleans indicating whether a pieces is finished or not.