Gentle trick-or-treaters, to steal a phrase from Miss Manners, please be respectful this Halloween. Sure, you're tromping door-to-door, begging for candy under the not-so-thinly veiled threat of inflicting mayhem. Sure, you might even be wearing a bloody mask and carrying a scythe. But this is no time to lose all sense of decorum and civility. Yes, that means you, you too-late doorbell ringer, you garden trampler, you candy hogger.