Support scheduled restarts

[HunterZ]

It may be desirable to perform a scheduled orderly restart for various reasons, e.g.:

• recover server FPS by resetting entity count
• perform daily update check when not using periodic updater

Need to test whether orderly shutdowns erase teams so that it can be documented. I've seen this happen on other servers, but have read that it may only occur when shutting down via a process terminate?

Probably want to allow normal delay processing to occur when players are online, in order to minimize disruption.

[HunterZ]

Update: Confirmed that orderly shutdowns preserve teams.

I've also heard confirmation that it's good to restart a server once every day or so, for performance reasons, so I'd like to be able to do this for my own server via RLS.

[HunterZ]

This is low priority for now, as I've got RLS running as a Windows service, and am using Task Scheduler to restart the service nightly.