Issue192

Created by: juga0

Fixes #192 (closed). It's catching all possible controller exceptions and logging them. If/when we know more details about why they happen, we might want to catch only those and do something different. In some cases we might want to return different to what it's now returned. This solution is almost the same as just letting the Exception raise. It seems that we could also use add_status_listener [0] to the controller, though i'm not sure now which functions we should call in the different situations.

[0] https://stem.torproject.org/api/control.html#stem.control.BaseController.add_status_listener