createTwoColumnLayout.js

function createTwoColumnLayout (itemsClassSelector) {
		var colCount = 1;
		var c = 0;
		if(itemsClassSelector.indexOf(".") > -1){
		 items = $(itemsClassSelector);
		}
		else{
		 items = $("."+itemsClassSelector);
		 itemsClassSelector = "."+itemsClassSelector
		}
 
		items.each(function () {
			var item = $(this);
			var children = item.children().first();
			item.addClass("sf_colsOut sf_2cols_" + colCount + "_50");
			children.addClass("sf_colsIn sf_2cols_" + colCount + "in_50");
			var t = c % 2;
			if (t === 1) {
				children.addClass("alt");
			}
			colCount++;
			if (colCount > 2) {
				var cols = $(":not(.sf_cols) > "+itemsClassSelector+ ".sf_colsOut.sf_2cols_1_50,"+" :not(.sf_cols) > "+itemsClassSelector+ ".sf_colsOut.sf_2cols_2_50");
				
				if (!cols.parent().hasClass("sf_cols")) {
					cols.wrapAll("<div class='sf_cols'></div>");
				}
				colCount = 1;
				c++;
			}
		});
		if (items.length % 2) {
				cols = $(itemsClassSelector+".sf_colsOut.sf_2cols_1_50").last();
				if (!cols.parent().hasClass("sf_cols") && cols.siblings(itemsClassSelector+ ".sf_colsOut.sf_2cols_2_50").length === 0) {
					cols.wrapAll("<div class='sf_cols'></div>").after("<div class='" + itemsClassSelector.replace(".","") + " sf_colsOut sf_2cols_2_50'><div class='sf_colsIn sf_2cols_2in_50'></div></div>");
				}
			}
}

If anyone finds a bug or has an improvement for the code above, please submit an issue or pull request here.