* Add flag to enable/disable timstamps for process log.
solves #2615
* Remove timestamp argument from log.Printf()
* Add log-timestamps=false to systemd unit
* Copy log flags
* Fix argument list
OnStartup and OnShutdown callbacks now run as part of restarts, too.
The startup and shutdown directives only run their commands NOT as part
of restarts, as before. Some middleware that use OnStartup may need to
switch to OnFirstStartup and implement OnFinalShutdown to do any cleanup
as needed.