peer comms beginning
more messages, added some tests
made tracker comms work
comments and some bugfixes
refactoring
Merge pull request #6 from danielkeller/peer_comms

Peer comms
Merge pull request #7 from danielkeller/nm_fix_tracker_comms

made tracker comms work
Removed peer_id from TorrentTracker method (because it was removed in a previous commit)