Allow modules to schedule themselves after the Broker has stopped

This is because we don't want anybody to go insane while attemping to
write a correct module.  Our code should facilitate emotional well-being
whenever possible.

Although I am pretty sure that I am not mentally disabled, throwing an
exception for scheduling something did call that into question.
Update the other Schedule function as well

Having two Schedule functions pretty much guarantees that they are going
to get out of sync.  Oh well.