function getBoxWidth(labelOpts, fontSize) {
	return labelOpts.usePointStyle && labelOpts.boxWidth > fontSize ?
		fontSize :
		labelOpts.boxWidth;
}
Helper function to get the box width based on the usePointStyle option
@param {object} labelopts - the label options on the legend
@param {number} fontSize - the label font size
@return {number} width of the color box area