code: function(target, x, y, range){
              x = x || target.x;
              y = y || target.y;
              range = range || RL.Util.getDistance(this.x, this.y, x, y);
              return {
                  x: x,
                  y: y,
                  range: range,
                  value: target
              };
          }
docs: Wraps a target object in a container object with x, y, range
  @method prepareTargetObject
  @param {Object} target
  @param {Number} [x=target.x]
  @param {Number} [y=target.y]
  @param {Number} [range] range from `this.x`, `this.y` to x,y
  @return {Object} result result object
  `
  return {
  x: x, // target x tile coord
  y: y, // target y tile coord
  range: range, // distance to target
  value: target // target object
  };
  `
  @return {Object} result.x target x tile coord
  @return {Object} result.y target y tile coord
  @return {Object} result.range distance to target
  @return {Object} result.value target object