Minor function signature adjustments

modules/pcjs/lib/cpu.js

@@ -277,13 +277,14 @@ CPU.prototype.powerUp = function(data, fRepower)
 };
 
 /**
- * powerDown(fSave)
+ * powerDown(fSave, fShutdown)
  *
  * @this {CPU}
  * @param {boolean} fSave
- * @return {Object|boolean}
+ * @param {boolean} [fShutdown]
+ * @return {Object|boolean} component state if fSave; otherwise, true if successful, false if failure
  */
-CPU.prototype.powerDown = function(fSave)
+CPU.prototype.powerDown = function(fSave, fShutdown)
 {
     /*
      * The Computer component (which is responsible for all powerDown and powerUp notifications)