(TK-92) Add graceful-shutdown support

Add graceful-shutdown support to the Jetty9 Webservice. Now,
when the webserver is shutdown, the server will give open
requests a chance to resolve themselves. Allow user to
configure the graceful shutdown stop timeout.
I don't really have an issue with doing a sleep during the test, but it'd be nice if it could be shorter?  But, since I asked you to change the granularity of the setting to seconds instead of millis, it may not be possible to make the sleep shorter, and if that's the case, no big deal.