Chart = function(item, config) {
		this.construct(item, config);
		return this;
	}
y mode returns the elements that hit-test at the current y coordinate
@function Chart.Interaction.modes.y
@param chart {chart} the chart we are returning items from
@param e {Event} the event we are find things at
@param options {IInteractionOptions} options to use
@return {Chart.Element[]} Array of elements that are under the point. If none are found, an empty array is returned