Whitespace fix: two blanks lines before new class def
check that handler exists before invoking on it
support for exchange and prefix configuration, some cleanup
Basic reconnection
backoff strategy for reconnect attempt, scheduled events in event loop to support this and support for multi-host urls
Minor improvements:

* implement send_notification() (just use send())
* fix serialization of exceptions
* remove unused conf options (can add them back if and when used)
Renaming of files for greater clarity
Split out various aspects of the driver into separate modules