fix ActionInterval serious performance problem.

this is a serious bug, it cause massive cpu consume.
if we have 1000 animate in active scene, this fix can reduce 5% performance, raise 70% perf locally!!!!!!!!!!!! .
because it have massive calls cocos2d::Vector constructor and de-constructor. 
Vector's constructor will also call "addRefForAllObjects"!!!!!


This problem is very, very serious,  and still has many similar errors in cocos2d-x.

we must use "auto&" sometimes, especially in update per frame.