function extend(destination, source) {
    // JScript DontEnum bug is not taken care of
    for (var property in source) {
      destination[property] = source[property];
    }
    return destination;
  }
Copies all enumerable properties of one object to another
@memberOf fabric.util.object
@method extend
@param {Object} destination Where to copy to
@param {Object} source Where to copy from