The new code in 3032535f56 would signal that the output has stopped to
the back-end and front-end, but the event used in the outputs themselves
to shut down the send thread would still be signaled, causing the next
connection to immediately stop as soon as it had started. This fixes it
so that the event does not get signaled unless the thread is active.
The ftl output gets very spammy (3-6 lines every 5 seconds),
this commit changes the loglevel of those messages to debug
so they do not clutter up the logs of users.
In case these messages are needed they can be re-enabled using
the '--verbose' flag.
(also fixes minor formatting issues)
