FME Server Maintenance Mode

I suppose you can do this now by going to /fmeserver/#/engines and under hosts, set the Engines to 0, which will basically prevent any service from running and add them to the queue (which you should probably clear before you set the number of engines back to however many you have).

We would like to see this maintenance mode as mode that can be:

1. Manually started and stopped by an administrator
2. Scheduled as a single event with a defined start and end time
3. Scheduled as a recurring event with the usual recurring schedule options, e.g. every Monday from 3am-4am, the first Thursday of the month from 8pm-9pm, etc.

It would also be helpful to have an option to either to force running jobs to stop when the event begins or wait until all existing jobs are finished before starting the mode (and not starting new jobs of course).