Small bug in jsonrpc when creating exceptions.
New exception 'EpisodeNotFoundException' when querying for a tv episode
that is no longer present.
- Add a get_version method to the service.
- Have the gui call the get_version when it starts.  It no match, fail
to start gui (with warning about restart needed)
- Service can now be stopped by sending it a 'SHUTDOWN' message (just
that text, nothing more).
Log start/finish/failure of downloads
Gui for downloads
bump to 0.0.6