FloatRange = function(min, max) {
            min = min || 0.0;
            max = typeof max === "number" ? max : 1.0;
            // swap if necessary
            if (min > max) {
              var t = max;
              max = min;
              min = t;
            }
            this.min = min;
            this.max = max;
            this.currValue = min;
          }
construct a new `FloatRange`
provides utilities for dealing with a range of Numbers.
@param {Number} [min=0] the minimum in the range
@param {Number} [max=1.0] the maximum in the range
@constructor