actors :: Proxy :: terminate_now
actor to terminate nowQueueing a ShutDownMessage before every other ones
	# Tell `actor` to terminate now
	# Queueing a ShutDownMessage before every other ones
	fun terminate_now do
		var msg = new ShutDownMessage
		actor.mailbox.unshift(msg)
	end
					lib/actors/actors.nit:151,2--156,4