Responsive .makeColumn()

Created by: Tuckie

makeColumn should be responsive to allow for a responsive semantic grid.

The responsive generate commands will probably have to be reworked as well to allow for one point of (variable) reference ( #gridSystem > .generate(12, 70px, 30px);)

Maybe a variables.responsive.less needs to be created?

Basic version of what I would like to be able to do:

.span-carousel {
    .makeColumn(5);
}
.span-news {
    .makeColumn(4);
}
@media (max-width: 979px) {
    .span-carousel {
        .makeColumn(9);
    }
    .span-news {
        .makeColumn(9);
    }
}