### off*([object, ]event, callback)* Remove a certain callback from an event chain.
function(obj, event, callback) {
		// Use jQuery to handle DOM events.
		if(underscore.isElement(obj) && $){ return $(obj).off(event, callback); }

		// Use internal handler for pubsub
		if(this.isString(obj)) { event = obj; obj = this; }

		// If there aren't any handlers for this event, don't do anything.
		if(this.isObject(obj.__event_handlers) && event in obj.__event_handlers) {
			obj.__event_handlers[event].remove(callback);
		}
		return this;
	}