#1487 (Mar 8, 2020, 8:33:13 AM)

#2770: Handle posix signals SIGTERM, SIGINT, SIGHUP gracefully

- Move working contents of Bungeecord.stop() to a separate function
named independentThreadStop() intended to be called from a separate thread.
- Added a new generic shutdown hook to call independentThreadStop when
the JVM begins shutting down.
(commit: 697f087)