message: added isPointDistinct
diff: *
  * @param a First point.
  * @param b Second point.
  + * @param withinDistance Optional distance to consider points equal.
  * @returns true if points are the same, false if they are not
  */
  export function isPointEqual(a: IPoint, b: IPoint, withinDistance?: number): boolean {
  }
  }
  + /**
  + * Find out if a point is distinct among an array of points.
  + *
  + * @param pointToCheck point to check.
  + * @param pointArray array of points.
  + * @param withinDistance Optional distance to consider points equal.
  + * @returns false if point is equal to any point in the array.
  + */
  + export function isPointDistinct(pointToCheck: IPoint, pointArray: IPoint[], withinDistance?: number) {
  + for (var i = 0; i < pointArray.length; i++) {
  + if (measure.isPointEqual(pointArray[i], pointToCheck, withinDistance)) {
  + return false;
  + }
  + }
  + return true;
  + }
  +
  /**
  * Find out if point is on a slope.
  *
  