RegisterForSleep - Form
Registers this active magic effect/alias/form to receive events when the player goes to sleep and when he wakes up. Only the specific form, alias, or magic effect that registered will get the event - it will not be relayed to attached aliases or magic effects.
Function RegisterForSleep() native
; Register for when the player goes to sleep and wakes up RegisterForSleep()
Aliases and quests will automatically unregister for this event when the quest stops. Active magic effects will automatically unregister when they are removed.