Removed SendRetry in favor of one Send function
Log messages that were just for debugging
Send errors when protocol is violated, retries otherwise
Daemon for running on a client machine, sans tests
Added 'Stop' method to server
Added 'Stop' method to the daemon
Added a simple test for the daemon

- Need more interesting tests
- Should merge daemonTest and transferTest, or break them up into
  smaller functions
Added a nil check.. should think about whether this is needed