dotToDot class

    Attributes

      picture - a dynamic array of points
      capacity - int - the amount of space allocated for the picture
      numPoints - int - the number of points in the picture

    Behaviours
      
      constructor - creates an picture with no points
      append(point) - appends a point to the end of the picture
      remove() - removes the last point from the end of the picture
      clear() - removes all points from the picture
      overload the [] operator - to find out what the ith point is and
                                 to modify the ith point
      size() - returns the number of points in the picture