Partial commit of state-saving routines (for reference).
Another partial commit for save-state routine (for reference).
The save-state is still buggy, but it is updating the properties file now.
This is a requirement of the assignment, that we stop a download and then
resume it, from the same state.  Closing our program with "quit" will save
the state (still badly) to the properties file, but we might consider
using the commands "pause" and "resume" for this functionality to be
tested.  I will continue with the "quit" option state-saving later on
Monday.  By my commits you should be able to pinpoint my efforts last
night for implementing persistent state. I was last trying to have the
properties file reset() if the output file is not found on initialization
of Bittorrent object.