Correcting AttributeError

Fixing a couple AttributeError issues spotted by gsathya...

https://trac.torproject.org/7988
https://trac.torproject.org/7978

And one introduced by moving stem's Flag enum.
Using stem's status listening

Dropping our status listening in favor of stem's.

One very minor point of regression is that we now rely on SIGNAL events to get
sighup notifications rather than listening to NOTICE events. The NOTICE
listener was a hack so dropping it moving forward is probably for the best.
Fixing NameError when rendering fingerprints

Fixing another stacktrace spotted by gsathya...

https://trac.torproject.org/7990
Expand the path to save log

Previously, saving to '~/foo.txt' would create a '~'
folder in pwd which wasn't intuitive. Now, the '~' is
expanded to the users $HOME dir.