Changed columnSets, gutterSets to objects from arrays.

The if statements checking the columnSets and gutterSets variables for undefined properties are always evaluated as true due to the column name values being pushed into arrays as opposed to being set as object properties.

This results in duplicate css rules being pushed into the style sheets when the script finds multiple data-column attributes of the same value in the html.  

As an example, 100 rows all with data-columns="15"  will generate thousands of duplicate rules for .cols-15.  The result is poor page load performance.  Converting to objects fixes the issue.