Implementation of log handler

In dl2, the python code provided "log handlers", which were initialized with every service:
https://github.com/project8/dragonfly/blob/dl2/master/bin/dragonfly#L103
And parsed the log messages and could provide action for any log message that exceeded a threshold value. In practice, this meant broadcasting logs that exceeded a threshold to the alerts exchange:
https://github.com/project8/dragonfly/blob/dl2/master/dragonfly/status_log_handlers/amqp_handler.py#L53
(where the slack service could push notifications to the appropriate slack channels)

In dl3, with logging integrated between cpp and python, this properly would need to move back into the cpp code to replicate.