Sorts the array in descending order.
This is a destructive action, and will modify the array in place.
@param {Array} a The Array object to operate on.
@returns {Array} The array sorted in descending order.
@function
function descending (a) {
                    if(!(a instanceof Array)) return a;
                    return a.sort(function (a, b) {
                        if(a !== undefined && a !== null) a = a.toString();
                        if(b !== undefined && b !== null) b = b.toString();
                        return a > b ? -1 : a < b ? 1 : 0;
                    });
                }