Extension of lazerwalker's Skeleton-SASS Sass adaptation of the Skeleton grid.

I include the original classes for backwards compatibility (especially with Spree, which I'm working with now).

I also include a poorly-named parameter for "border-width" to the column mixins which allows you to adjust the column width to account for any border and/or padding you have added to the element.

Note that the responsive parts are commented out in the mixin definitions because my client didn't like things moving around. I think it's best to assume that the layout shouldn't respond to a different screen size until the specific response is properly designed. At that point, you can uncomment it.