A port of nl2br to Underscore

underscore.nl2br

_.mixin({
	nl2br : function(str, is_xhtml){
		var breakTag = (is_xhtml || typeof is_xhtml === 'undefined') ? '<br />' : '<br>';
		return (str + '').replace(/([^>\r\n]?)(\r\n|\n\r|\r|\n)/g, '$1' + breakTag + '$2');
	}
});