Updated class module docblock

lib/class.js

@@ -43,7 +43,8 @@ var class_meta = {};
  * use the class's extend() method. If unavailable (or extending a non-ease.js
  * class/object), use the module's extend() method.
  *
- * @param  {Object}  def  class definition
+ * @param  {string=}  name  optional name
+ * @param  {Object}   def   class definition
  *
  * @return  {Class}  new class
  */